WorldWideScience

Sample records for bio-nanocomposite films based

  1. Effect of type and content of modified montmorillonite on the structure and properties of bio-nanocomposite films based on soy protein isolate and montmorillonite.

    Science.gov (United States)

    Kumar, P; Sandeep, K P; Alavi, S; Truong, V D; Gorga, R E

    2010-06-01

    The nonbiodegradable and nonrenewable nature of plastic packaging has led to a renewed interest in packaging materials based on bio-nanocomposites (biopolymer matrix reinforced with nanoparticles such as layered silicates). Bio-nanocomposite films based on soy protein isolate (SPI) and modified montmorillonite (MMT) were prepared using melt extrusion. The effect of different type (Cloisite 20A and Cloisite 30B) and content (0% to 15%) of modified MMT on the structure (degree of intercalation and exfoliation) and properties (color, mechanical, dynamic mechanical, thermal stability, and water vapor permeability) of SPI-MMT bio-nanocomposite films were investigated. Extrusion of SPI and modified MMTs resulted in bio-nanocomposites with exfoliated structures at lower MMT content (5%). At higher MMT content (15%), the structure of bio-nanocomposites ranged from intercalated for Cloisite 20A to disordered intercalated for Cloisite 30B. At an MMT content of 5%, bio-nanocomposite films based on modified MMTs (Cloisite 20A and Cloisite 30B) had better mechanical (tensile strength and percent elongation at break), dynamic mechanical (glass transition temperature and storage modulus), and water barrier properties as compared to those based on natural MMT (Cloisite Na(+)). Bio-nanocomposite films based on 10% Cloisite 30B had mechanical properties comparable to those of some of the plastics that are currently used in food packaging applications. However, much higher WVP values of these films as compared to those of existing plastics might limit the application of these films to packaging of high moisture foods such as fresh fruits and vegetables.

  2. Physicochemical and antifungal properties of bio-nanocomposite film based on gelatin-chitin nanoparticles.

    Science.gov (United States)

    Sahraee, Samar; Milani, Jafar M; Ghanbarzadeh, Babak; Hamishehkar, Hamed

    2017-04-01

    The gelatin-based nanocomposite films containing chitin nanoparticles (N-chitin) with concentrations of 0, 3, 5 and 10% were prepared and their physical, thermal and anti-microbial properties were investigated. Scanning electron microscopy (SEM) micrographs showed that N-chitin size distribution was around 60-70nm which dispersed appropriately at low concentration in gelatin matrix. The results showed that incorporation of N-chitin significantly influenced apparent color and transparency of the gelatin films. The reduced water vapor permeability (WVP) and solubility and higher surface hydrophobicity of the nanocomposite films were obtained by enhancing N-chitin concentration in film formulation. The use of N-chitin up to 5% concentration in the gelatin based nanocomposite film led to improved mechanical properties. Also, the results of differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) confirmed improved stability of nanocomposite films against melting and degradation at high temperatures in comparison to neat gelatin film. The well compatibility of chitin nanoparticles with gelatin polymer was concluded from Fourier transform infrared (FTIR) spectra and X-ray diffraction (XRD) plots. Finally, the gelatin based nanocomposite films had anti-fungal properties against Aspergillus niger in the contact surface zone. Increasing the concentration of N-chitin up to 5% enlarged inhibition zone diameter, but the nanocomposite film containing 10% N-chitin showed smaller inhibition zone. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Effect of halloysite content on carboxymethyl cellulose/halloysite nanotube bio-nanocomposite films

    Science.gov (United States)

    Suppiah, Kathiravan; Leng, Teh Pei; Husseinsyah, Salmah; Rahman, Rozyanty; Keat, Yeoh Cheow

    2017-04-01

    Carboxymethyl cellulose/halloysite nanotube (CMC/HNT) bio-nanocomposite films were prepared by solution casting method. The effect of HNT content on tensile properties and morphology were studied. The results showed that the tensile strength of the CMC/HNT bio-nanocomposite films achieved optimum at 10 wt% of HNT content. The elongation at break and modulus of elasticity increased with increasing HNT content. The morphology of CMC/HNT bio-nanocomposite films showed that the poor distribution of HNT filler was observed at 20 wt% of HNT content.

  4. Mechanical and solubility properties of bio-nanocomposite film of semi refined kappa carrageenan/ZnO nanoparticles

    Science.gov (United States)

    Saputri, Apriliana Eka; Praseptiangga, Danar; Rochima, Emma; Panatarani, Camellia; Joni, I. Made

    2018-02-01

    The aim of this present work is to develop semi refined kappa carrageenan based bio-nanocomposite film as an alternative to synthetic petroleum based food packaging materials. Among natural polymers, carrageenan is one of the most promising material, since it is a renewable bioresource. The ZnO nanoparticles (0.5%; 1.0%; 1.5% w/w carrageenan) was incorporated into carrageenan polymer to prepare bio-nanocomposite films, where ZnO acts as reinforcement for carrageenan matrix. The mechanical and solubility properties of the prepared films were investigated as a function of ZnO concentration. The results indicated that the addition of ZnO exhibits greater solubility compared to the neat film. The elongation at break is insignificantly different on the films with and without addition ZnO. The tensile strength of the film was highest for the sample with 0.5% ZnO. These mechanical and solubility properties suggest that bio-nanocomposite film of semi refined kappa carrageenan and nanoparticle ZnO can be effectively used as food packaging material.

  5. Cytotoxicity and mechanical behavior of chitin-bentonite clay based polyurethane bio-nanocomposites.

    Science.gov (United States)

    Zia, Khalid Mahmood; Zuber, Mohammad; Barikani, Mehdi; Hussain, Rizwan; Jamil, Tahir; Anjum, Sohail

    2011-12-01

    Chitin based polyurethane bio-nanocomposites (PUBNC) were prepared using chitin, Delite HPS bentonite nanoclay enriched in montmorillonite (MMT), 4,4'-diphenylmethane diisocyanate (MDI) and polycaprolactone polyol CAPA 231 (3000 g/mol(-1)). The prepolymers having different concentration of Delite HPS bentonite nanoclay were extended with 2 moles of chitin. The structures of the resulted polymers were determined by FT-IR technique. The effect of nanoclay contents on mechanical properties and in vitro biocompatibility was investigated. The mechanical properties of the synthesized materials were improved with increase in the Delite HPS bentonite nanoclay contents. Optimum mechanical properties were obtained from the PU bio-nanocomposite samples having 4% Delite HPS bentonite nanoclay. The results revealed that the final PU bio-nanocomposite having 2% Delite HPS bentonite nanoclay contents is ideal contenders for surgical threads with on going investigations into their in vitro biocompatibility, non-toxicity, and mechanical properties. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Processing and properties of eco-friendly bio-nanocomposite films filled with cellulose nanocrystals from sugarcane bagasse.

    Science.gov (United States)

    El Achaby, Mounir; El Miri, Nassima; Aboulkas, Adil; Zahouily, Mohamed; Bilal, Essaid; Barakat, Abdellatif; Solhy, Abderrahim

    2017-03-01

    Novel synthesis strategy of eco-friendly bio-nanocomposite films have been exploited using cellulose nanocrystals (CNC) and polyvinyl alcohol/carboxymethyl cellulose (PVA/CMC) blend matrix as a potential in food packaging application. The CNC were extracted from sugarcane bagasse using sulfuric acid hydrolysis, and they were successfully characterized regarding their morphology, size, crystallinity and thermal stability. Thereafter, PVA/CMC-CNC bio-nanocomposite films, at various CNC contents (0.5-10wt%), were fabricated by the solvent casting method, and their properties were investigated. It was found that the addition of 5wt% CNC within a PVA/CMC increased the tensile modulus and strength by 141% and 83% respectively, and the water vapor permeability was reduced by 87%. Additionally, the bio-nanocomposites maintained the same transparency level of the PVA/CMC blend film (transmittance of ∼90% in the visible region), suggesting that the CNC were dispersed at the nanoscale. In these bio-nanocomposites, the adhesion properties and the large number of functional groups that are present in the CNC's surface and the macromolecular chains of the PVA/CMC blend are exploited to improve the interfacial interactions between the CNC and the blend. Consequently, these eco-friendly structured bio-nanocomposites with superior properties are expected to be useful in food packaging applications. Copyright © 2016. Published by Elsevier B.V.

  7. Novel electrochemical xanthine biosensor based on chitosan–polypyrrole–gold nanoparticles hybrid bio-nanocomposite platform

    Directory of Open Access Journals (Sweden)

    Muamer Dervisevic

    2017-07-01

    Full Text Available The aim of this study was the electrochemical detection of the adenosine-3-phosphate degradation product, xanthine, using a new xanthine biosensor based on a hybrid bio-nanocomposite platform which has been successfully employed in the evaluation of meat freshness. In the design of the amperometric xanthine biosensor, chitosan–polypyrrole–gold nanoparticles fabricated by an in situ chemical synthesis method on a glassy carbon electrode surface was used to enhance electron transfer and to provide good enzyme affinity. Electrochemical studies were carried out by the modified electrode with immobilized xanthine oxidase on it, after which the biosensor was tested to ascertain the optimization parameters. The Biosensor exhibited a very good linear range of 1–200 μM, low detection limit of 0.25 μM, average response time of 8 seconds, and was not prone to significant interference from uric acid, ascorbic acid, glucose, and sodium benzoate. The resulting bio-nanocomposite xanthine biosensor was tested with fish, beef, and chicken real-sample measurements.

  8. High Performances of Artificial Nacre-Like Graphene Oxide-Carrageenan Bio-Nanocomposite Films.

    Science.gov (United States)

    Zhu, Wenkun; Chen, Tao; Li, Yi; Lei, Jia; Chen, Xin; Yao, Weitang; Duan, Tao

    2017-05-16

    This study was inspired by the unique multi-scale and multi-level 'brick-and-mortar' (B&M) structure of nacre layers. We prepared the B&M, environmentally-friendly graphene oxide-carrageenan (GO-Car) nanocomposite films using the following steps. A natural polyhydroxy polymer, carrageenan, was absorbed on the surface of monolayer GO nanosheets through hydrogen-bond interactions. Following this, a GO-Car hybridized film was produced through a natural drying process. We conducted structural characterization in addition to analyzing mechanical properties and cytotoxicity of the films. Scanning electron microscope (SEM) and X-ray diffraction (XRD) analyses showed that the nanocomposite films had a similar morphology and structure to nacre. Furthermore, the results from Fourier transform infrared spectroscopy (FT-IR), Raman spectroscopy, X-ray photoelectron spectroscopy (XPS) and Thermogravimetric (TG/DTG) were used to explain the GO-Car interaction. Analysis from static mechanical testers showed that GO-Car had enhanced Young's modulus, maximum tensile strength and breaking elongation compared to pure GO. The GO-Car nanocomposite films, containing 5% wt. of Car, was able to reach a tensile strength of 117 MPa. The biocompatibility was demonstrated using a RAW264.7 cell test, with no significant alteration found in cellular morphology and cytotoxicity. The preparation process for GO-Car films is simple and requires little time, with GO-Car films also having favorable biocompatibility and mechanical properties. These advantages make GO-Car nanocomposite films promising materials in replacing traditional petroleum-based plastics and tissue engineering-oriented support materials.

  9. High Performances of Artificial Nacre-Like Graphene Oxide-Carrageenan Bio-Nanocomposite Films

    Directory of Open Access Journals (Sweden)

    Wenkun Zhu

    2017-05-01

    Full Text Available This study was inspired by the unique multi-scale and multi-level ‘brick-and-mortar’ (B&M structure of nacre layers. We prepared the B&M, environmentally-friendly graphene oxide-carrageenan (GO-Car nanocomposite films using the following steps. A natural polyhydroxy polymer, carrageenan, was absorbed on the surface of monolayer GO nanosheets through hydrogen-bond interactions. Following this, a GO-Car hybridized film was produced through a natural drying process. We conducted structural characterization in addition to analyzing mechanical properties and cytotoxicity of the films. Scanning electron microscope (SEM and X-ray diffraction (XRD analyses showed that the nanocomposite films had a similar morphology and structure to nacre. Furthermore, the results from Fourier transform infrared spectroscopy (FT-IR, Raman spectroscopy, X-ray photoelectron spectroscopy (XPS and Thermogravimetric (TG/DTG were used to explain the GO-Car interaction. Analysis from static mechanical testers showed that GO-Car had enhanced Young’s modulus, maximum tensile strength and breaking elongation compared to pure GO. The GO-Car nanocomposite films, containing 5% wt. of Car, was able to reach a tensile strength of 117 MPa. The biocompatibility was demonstrated using a RAW264.7 cell test, with no significant alteration found in cellular morphology and cytotoxicity. The preparation process for GO-Car films is simple and requires little time, with GO-Car films also having favorable biocompatibility and mechanical properties. These advantages make GO-Car nanocomposite films promising materials in replacing traditional petroleum-based plastics and tissue engineering-oriented support materials.

  10. Cytoxicity, dynamic and thermal properties of bio-based rosin-epoxy resin/ castor oil polyurethane/ carbon nanotubes bio-nanocomposites.

    Science.gov (United States)

    Huo, Li; Wang, Dan; Liu, Hongmei; Jia, Pan; Gao, Jungang

    2016-08-01

    In order to prepare bio-nanocomposites with no-cytotoxicity, the rosin-based epoxy resin (MPAER) and castor oil-based polyurethane (COPU) were synthesized and carbon nanotubes (CNTs) was used to enhance the properties of curing MPAER/COPU materials. The curing reaction, dynamic mechanical and thermal properties of this system were characterized by FTIR, NMR, DMA, TG et al. The cytotoxicity of materials is evaluated for HeLa cells using a MTT cell-viability assay. The results showed that COPU can cure MPAER and CNTs can increase effectively the properties of MPAER/COPU nanocomposites. The Tg of MPAER/COPU/CNTs has the highest value when CNTs content is 0.4 wt%, which is 52.4 °C higher than the pure MPAER/COPU. Thermal stability of the nanocomposites is enhanced by the addition of CNTs, the initial decomposition temperature Td5 of the sample No. 0.4 has increased from 284.5 to 305.2 °C, which is 20.7 °C higher than No. 0. The impact strength of the No. 0.4 film is 15 kg cm higher than the pure resin system. The survival rate of HeLa cells to the products is greater than 90% within 48 and 72 h, which demonstrate that this material has excellent biocompatibility and no obvious cytotoxicity for HeLa cells, which may be used in the medical treatment.

  11. Development of photo-modified starch/kefiran/TiO2 bio-nanocomposite as an environmentally-friendly food packaging material.

    Science.gov (United States)

    Goudarzi, Vahid; Shahabi-Ghahfarrokhi, Iman

    2018-05-21

    This paper reports on an experiment in which starch/kefiran/TiO 2 (SKT)-based bio-nanocomposite films were developed and modified by photo-chemical reaction. In so doing, film-forming solutions were exposed to ultraviolet A (UV-A) for different times (1, 6, and 12 h). The obtained results indicated that increasing UV-A exposure time brought about an increase (≈14.9%) in the tensile strength of bio-nanocomposites. However, elongation at break and Young's modulus of irradiated film specimen decreased (≈32%, ≈12%, respectively) by increasing UV-A exposure time, and the moisture-sensitive parameters of specimen decreased using UV-A irradiation. According to the results, the functional properties of irradiated bio-nanocomposite are depended on the ratio of cross-linkages between polymer chains and the potentially produced mono and disaccharide by UV-A. Copyright © 2018. Published by Elsevier B.V.

  12. Simultaneous immobilization of cadmium and lead in contaminated soils by hybrid bio-nanocomposites of fungal hyphae and nano-hydroxyapatites.

    Science.gov (United States)

    Yang, Zhihui; Liang, Lifen; Yang, Weichun; Shi, Wei; Tong, Yunping; Chai, Liyuan; Gao, Shikang; Liao, Qi

    2018-04-01

    Self-aggregation of bulk nano-hydroxyapatites (n-HAPs) undermines their immobilization efficiencies of heavy metals in the contaminated soils. Here, the low-cost, easily obtained, and environment-friendly filamentous fungi have been introduced for the bio-matrices of the hybrid bio-nanocomposites to potentially solve such problem of n-HAPs. According to SEM, TEM, XRD, and FT-IR analyses, n-HAPs were successfully coated onto the fungal hyphae and their self-aggregation was improved. The immobilization efficiencies of diethylene-triamine-pentaacetic acid (DTPA)-extractable Cd and Pb in the contaminated soils by the bio-nanocomposites were individually one to four times of that by n-HAPs or the fungal hyphae. Moreover, the Aspergillus niger-based bio-nanocomposite (ANHP) was superior to the Penicillium Chrysogenum F1-based bio-nanocomposite (PCHP) in immobilization of Cd and Pb in the contaminated soils. In addition, the results of XRD showed that one of the potential mechanisms of metal immobilization by the hybrid bio-nanocomposites was dissolution of n-HAPs followed by precipitation of new metal phosphate minerals. Our results suggest that the hybrid bio-nanocomposite (ANHP) can be recognized as a promising soil amendment candidate for effective remediation on the soils simultaneously contaminated by Cd and Pb.

  13. Mechanical and optical characterization of bio-nanocomposite from pineapple leaf fiber material for food packaging

    Science.gov (United States)

    Nikmatin, Siti; Rudwiyanti, Jerry R.; Prasetyo, Kurnia W.; Yedi, Dwi A.

    2015-01-01

    The utilization of Bio-nanocomposite material that was derived from pineapple leaf fiber as filler and tapioca starch with plasticizer glycerol as a matrix for food packaging can reduce the use of plastic that usually was made from petroleum materials. It is important to develop and producethis environmental friendly plastic because of limited availability of petroleum nowadays. The process of synthesize and characterization tapioca starch with the plasticizer glycerol bionanocomposites using print method had been conducted. There were 3 samples with different filler concentration variation; 3%, 4% and 5%.The results of mechanical test from each sample showed that bio-nanocomposite with 5% filler concentration was the optimum sample with 4.6320 MPa for tensile strength test and 24.87% for the elongation test. Based on the result of optical test for each sample was gained that along with the increasing of concentration filler would make the absorbance value of the sample became decreased, bio-nanocomposite with 5% filler concentration had several peaks with low absorbance values. The first peak was in 253 nm of wavelength regionwith absorbance of 0.131%, and the second peak was in 343 nmwavelength region and absorbance was 0.087%.

  14. Improvement of barrier and mechanical properties of whey protein isolate based food packaging films by incorporation of zein nanoparticles as a novel bionanocomposite

    OpenAIRE

    Oymacı, Pelin; Alsoy Altınkaya, Sacide

    2016-01-01

    In this study, whey protein isolate (WPI) based bio-nanocomposite films embedded with zein nanoparticles (ZNP) were prepared by solution casting. Nanoparticles were coated with sodium caseinate to obtain a uniform distribution in the films. The mechanical, water vapor barrier, surface wetting, morphological and viscoelastic properties of the films were investigated. The addition of ZNP significantly improved the water vapor barrier and mechanical properties of the WPI without adversely affect...

  15. Transmission electron microscopy of polyhydroxybutyrate-co-valerate (PHBV)/nanocrystalline cellulose (NCC) bio-nanocomposite prepared using cryo-ultramicrotomy

    Science.gov (United States)

    Ismarul, N. I.; Engku, A. H. E. U.; Siti, N. K.; Tay, K. Y.

    2017-12-01

    Environmental issues on disposal and end-of-life for product made from synthetic petroleum-derived polymers have gained increasing attention from materials scientist to search for new materials with similar physical and mechanical properties but environmental friendly in a way that they are renewable and biodegradable as well. This work is to study the effect of nanocrystalline cellulose in improving the thermal stability of polyhydroxybutyrate-co-valerate biopolymer for high temperature processing of packaging material. 10 % w/w PHBV-NCC bio-nanocomposite feedstock pellet prepared using RONDOL minilab compounder was used as the sample for the preparation of Transmission Electron Microscopy (TEM) sample. RMC Cryo-Ultramicrotomy equipment was used to prepare the ultra-thin slice of the bio-nanocomposite pellet under liquid nitrogen at - 60 °C. Diamond knife was used to slice off about 80-100 nm ultra-thin bio-nanocomposite films and was transferred into the lacey carbon film coated grid using cooled sugar solution. A few drops of phosphotungstic acid was used as negative stain to improve the contrast during the TEM analysis. HITACHI TEM systems was used to obtain the TEM micrograph of PHBV-NCC bio-nanocomposite using 80kV accelerating voltage. A well dispersed NCC in PHBV matrix, ranging from 5 to 25 nm in width was observed.

  16. Simple method for preparing glucose biosensor based on in-situ polypyrrole cross-linked chitosan/glucose oxidase/gold bionanocomposite film.

    Science.gov (United States)

    Şenel, Mehmet

    2015-03-01

    A film of chitosan-polypyrrole-gold nanoparticles was fabricated by in-situ chemical synthesis method and its application in glucose biosensor was investigated. The obtained biosensor exhibited a high and reproducible sensitivity of 0.58μA/mM, response time ~4s, linear dynamic range from 1 to 20mM, correlation coefficient of R(2)=0.9981, and limit of detection (LOD), based on S/N ratio (S/N=3) of 0.068mM. A value of 1.83mM for the apparent Michaelis-Menten constant was obtained. The resulting bio-nanocomposite provided a suitable environment for the enzyme to retain its bioactivity at considerably extreme conditions, and the decorated gold nanoparticles in the bio-nanocomposite offer good affinity to enzyme. Copyright © 2014. Published by Elsevier B.V.

  17. Fabrication, nanomechanical characterization, and cytocompatibility of gold-reinforced chitosan bio-nanocomposites

    International Nuclear Information System (INIS)

    Patel, Nimitt G.; Kumar, Ajeet; Jayawardana, Veroni N.; Woodworth, Craig D.; Yuya, Philip A.

    2014-01-01

    Chitosan, a naturally derived polymer represents one of the most technologically important classes of active materials with applications in a variety of industrial and biomedical fields. Gold nanoparticles (∼ 32 nm) were synthesized via a citrate reduction method from chloroauric acid and incorporated in Chitosan matrix. Bio-nanocomposite films with varying concentrations of gold nanoparticles were prepared through solution casting process. Uniform distribution of gold nanoparticles was achieved throughout the chitosan matrix and was confirmed with SEM. Synthesis outcomes and prepared nanocomposites were characterized using SEM, TEM, EDX, SAED, UV–vis, XRD, DLS, and Zeta potential for their physical, morphological and structural properties. Nanoscale properties of materials under the influence of temperature were characterized through nanoindentation techniques. From quasi-static nanoindentation, it was observed that hardness and reduced modulus of the nanocomposites were increased significantly in direct proportion to the gold nanoparticle concentration. Gold nanoparticle concentration also showed positive impact on storage modulus and thermal stability of the material. The obtained films were confirmed to be biocompatible by their ability to support growth of human cells in vitro. In summary, the results show enhanced mechanical properties with increasing gold nanoparticle concentration, and provide better understanding of the structure–property relationships of such biocompatible materials for potential biomedical applications. - Highlights: • We fabricated gold reinforced chitosan nanocomposite for biomedical applications. • Gold nanoparticles significantly enhanced nanomechanical properties of chitosan. • Nanocomposite films supported growth of human cells in vitro. • Gold nanoparticles significantly improved cell proliferation on chitosan films

  18. Preparation and Properties of Cellulose Laurate (CL/Starch Nanocrystals Acetate (SNA Bio-nanocomposites

    Directory of Open Access Journals (Sweden)

    Feng-Yuan Huang

    2015-07-01

    Full Text Available In the present paper, a series of totally novel bio-nanocomposite films from cellulose laurate (CL and starch nanocrystals acetate (SNA were fabricated, and the properties of nanocomposite films were investigated in detail. SNA was obtained by modifying starch nanocrystals (SNs produced by sulfuric acid hydrolysis of corn starch with acetic anhydride. The favorable dispersity of SNA in chloroform made it ready to convert into nanocomposite films with CL via casting/evaporation method. The transmittance, thermal behavior, mechanical properties, barrier properties and hydrophobicity of CL/SNA nanocomposite films were investigated with UV-vis spectrophotometer, simultaneous thermal analyzer (STA, universal tensile tester/dynamic thermomechanical analysis (DMA, water vapor permeation meter/oxygen permeability tester, and contact angle tester, respectively. The transmittance of nanocomposite films decreased with the increase of SNA content. Thermogravimetric analysis (TGA results showed that the introduction of SNA into CL matrix did not severely decrease the thermal behavior of CL/SNA nanocomposites. Moreover, non-linear and linear mechanical analysis reflected the enhancement of SNA. At lower contents of SNA (<5.0 wt%, the values of Young’s modulus, tensile strength and the elongation at break of nanocomposite films were comparable with those of neat CL. However, with the increase of SNA, the Young’s modulus and tensile strength were improved significantly and were accompanied by the decreased elongation at break. The water vapor permeability (WVP and oxygen permeability (PO2 of CL/SNA nanocomposite films were significantly improved by the addition of SNA.

  19. Development of polylactic acid nanocomposite films reinforced with cellulose nanocrystals derived from coffee silverskin.

    Science.gov (United States)

    Sung, Soo Hyun; Chang, Yoonjee; Han, Jaejoon

    2017-08-01

    Bio-nanocomposite films based on polylactic acid (PLA) matrix reinforced with cellulose nanocrystals (CNCs) were developed using a twin-screw extruder. The CNCs were extracted from coffee silverskin (CS), which is a by-product of the coffee roasting process. They were extracted by alkali treatment followed by sulfuric acid hydrolysis. They were used as reinforcing agents to obtain PLA/CNC nanocomposites by addition at different concentrations (1%, 3%, and 5% CNCs). Morphological, tensile, and barrier properties of the bio-nanocomposites were analyzed. The tensile strength and Young's modulus increased with both 1% and 3% CNCs. The water vapor permeability decreased gradually with increasing addition of CNCs up to 3% and good oxygen barrier properties were found for all nanocomposites. These results suggest that CNCs from CS can improve the physical properties of PLA-based biopolymer film. The developed PLA/CNC bio-nanocomposite films can potentially be used for biopolymer materials with enhanced barrier and mechanical properties. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Effect of gamma ray on magnetic bio-nanocomposite

    International Nuclear Information System (INIS)

    Asadi, Sima; Frounchi, Masoud; Dadbin, Susan

    2016-01-01

    Magnetic polyvinyl alcohol (M-PVA) films were prepared via solution casting filled with surface modified superparamagnetic nanoparticles (M-NPs). The M-NPs were coated with citric acid during synthesis. The chemical interaction between the citric acid and M-NPs was confirmed by Fourier transform infrared spectroscopy (FTIR). The average hydrodynamic diameter of M-NPs was 19.7 nm measured by dynamic light scattering DLS and appeared almost spherical in scanning electron microscopy (SEM). The M-NPs were uniformly dispersed in polyvinyl alcohol (PVA) matrix and showed high optical transparency with good mechanical properties. M-PVA hydrogels were synthesized using gamma irradiation. The characteristic XRD peak of PVA at 19.4° was split after irradiation indicating formation of different crystallite sizes. The M-PVA hydrogel showed higher saturation magnetization compared to un-irradiated M-PVA. Also the presence of M-NPs enhanced the crosslinking of PVA by irradiation. - Highlights: • PVA and Fe 3 O 4 nanocomposite films and hydrogels were prepared. • Gamma-irradiated hydrogels showed high saturation magnetization. • The nanocomposite films had excellent mechanical properties. • Magnetic hydrogels showed high equilibrium water content.

  1. Effect of gamma ray on magnetic bio-nanocomposite

    Energy Technology Data Exchange (ETDEWEB)

    Asadi, Sima [Sharif University of Technology, Department of Chemical and Petroleum Engineering, Tehran (Iran, Islamic Republic of); Frounchi, Masoud, E-mail: frounchi@sharif.edu [Sharif University of Technology, Department of Chemical and Petroleum Engineering, Tehran (Iran, Islamic Republic of); Dadbin, Susan [Radiation Applications Research School, Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of)

    2016-02-15

    Magnetic polyvinyl alcohol (M-PVA) films were prepared via solution casting filled with surface modified superparamagnetic nanoparticles (M-NPs). The M-NPs were coated with citric acid during synthesis. The chemical interaction between the citric acid and M-NPs was confirmed by Fourier transform infrared spectroscopy (FTIR). The average hydrodynamic diameter of M-NPs was 19.7 nm measured by dynamic light scattering DLS and appeared almost spherical in scanning electron microscopy (SEM). The M-NPs were uniformly dispersed in polyvinyl alcohol (PVA) matrix and showed high optical transparency with good mechanical properties. M-PVA hydrogels were synthesized using gamma irradiation. The characteristic XRD peak of PVA at 19.4° was split after irradiation indicating formation of different crystallite sizes. The M-PVA hydrogel showed higher saturation magnetization compared to un-irradiated M-PVA. Also the presence of M-NPs enhanced the crosslinking of PVA by irradiation. - Highlights: • PVA and Fe{sub 3}O{sub 4} nanocomposite films and hydrogels were prepared. • Gamma-irradiated hydrogels showed high saturation magnetization. • The nanocomposite films had excellent mechanical properties. • Magnetic hydrogels showed high equilibrium water content.

  2. Preparation and characterization of antibacterial Senegalia (Acacia) senegal/iron–silica bio-nanocomposites

    International Nuclear Information System (INIS)

    Şişmanoğlu, Tuba; Karakuş, Selcan; Birer, Özgür; Soylu, Gülin Selda Pozan; Kolan, Ayşen; Tan, Ezgi; Ürk, Öykü; Akdut, Gizem; Kilislioglu, Ayben

    2015-01-01

    Many studies that research bio-nanocomposites utilize techniques that involve the dispersion of strengthening components like silica, metal and metal oxides through a host biopolymer matrix. The biggest success factor for the bio-nanocomposite is having a smooth integration of organic and inorganic phases. This interattraction between the surfaces of inorganic particles and organic molecules are vital for good dispersion. In this study, a novel biodegradable antibacterial material was developed using gum arabic from Senegalia senegal (stabilizer), silica (structure reinforcer) and zero valent iron particles. Silica particles work to not only strengthen the mechanical properties of the Senegalia senegal but also prevent the accumulation of ZVI nanoparticles due to attraction between hydroxyl groups and FeO. The gum arabic/Fe–SiO 2 bio-nanocomposite showed effective antibacterial property against the Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. Using Scanning electron microscopy, homogeneous dispersion and uniform particle size was viewed in the biopolymer. X-ray diffraction studies of iron particles organization in Senegalia senegal also showed that the main portion of iron was crystalline and in the form of FeO and Fe 0 . X-ray photoelectron spectroscopy was used to evaluate the chemical composition of the surface but no appreciable peak was measured for the iron before Ar etching. These results suggest that the surface of iron nanoparticles consist mainly of a layer of iron oxides in the form of FeO. Thermal gravimetric analysis was used to determine the thermal stability and absorbed moisture content.

  3. Preparation and characterization of antibacterial Senegalia (Acacia) senegal/iron–silica bio-nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Şişmanoğlu, Tuba; Karakuş, Selcan [Istanbul University, Faculty of Engineering, Department of Chemistry, 34320 Avcilar, Istanbul (Turkey); Birer, Özgür [Koç University, Department of Chemistry, Sarıyer 34450, Istanbul (Turkey); Koç University, KUYTAM Surface Science and Technology Center, Sarıyer 34450, Istanbul (Turkey); Soylu, Gülin Selda Pozan [Istanbul University, Faculty of Engineering, Department of Chemical Engineering, 34320 Avcilar, Istanbul (Turkey); Kolan, Ayşen; Tan, Ezgi; Ürk, Öykü; Akdut, Gizem [Istanbul University, Faculty of Engineering, Department of Chemistry, 34320 Avcilar, Istanbul (Turkey); Kilislioglu, Ayben, E-mail: ayben@istanbul.edu.tr [Istanbul University, Faculty of Engineering, Department of Chemistry, 34320 Avcilar, Istanbul (Turkey)

    2015-11-01

    Many studies that research bio-nanocomposites utilize techniques that involve the dispersion of strengthening components like silica, metal and metal oxides through a host biopolymer matrix. The biggest success factor for the bio-nanocomposite is having a smooth integration of organic and inorganic phases. This interattraction between the surfaces of inorganic particles and organic molecules are vital for good dispersion. In this study, a novel biodegradable antibacterial material was developed using gum arabic from Senegalia senegal (stabilizer), silica (structure reinforcer) and zero valent iron particles. Silica particles work to not only strengthen the mechanical properties of the Senegalia senegal but also prevent the accumulation of ZVI nanoparticles due to attraction between hydroxyl groups and FeO. The gum arabic/Fe–SiO{sub 2} bio-nanocomposite showed effective antibacterial property against the Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli. Using Scanning electron microscopy, homogeneous dispersion and uniform particle size was viewed in the biopolymer. X-ray diffraction studies of iron particles organization in Senegalia senegal also showed that the main portion of iron was crystalline and in the form of FeO and Fe{sup 0}. X-ray photoelectron spectroscopy was used to evaluate the chemical composition of the surface but no appreciable peak was measured for the iron before Ar etching. These results suggest that the surface of iron nanoparticles consist mainly of a layer of iron oxides in the form of FeO. Thermal gravimetric analysis was used to determine the thermal stability and absorbed moisture content.

  4. Preparation and characterization of bionanocomposite films based on potato starch/halloysite nanoclay.

    Science.gov (United States)

    Sadegh-Hassani, Fatemeh; Mohammadi Nafchi, Abdorreza

    2014-06-01

    In this research casting method was used to prepare potato starch based bio-nanocomposite films with halloysite nanoclay as the reinforcing materials. The composition included potato starch with 40% (w/w) of a mixture of sorbitol/glycerol (weight ratio of 3 to 1as plasticizer) with nanoclay (0-5% w/w). The films were dried under controlled conditions. Physicochemical properties such as solubility in water, water absorption capacity (WAC), water vapour permeability (WVP), oxygen permeability, and mechanical properties of the films were measured. Results showed that by increasing the concentration of nanoclay, mechanical properties of films were improved. Tensile strength was increased from 7.33 to 9.82MPa, and elongation at break decreased from 68.0 to 44.0%. Solubility in water decreased from 35 to 23%, and heat seal strength increased from 375 to 580N/m. Also incorporation of clay nanoparticles in the structure of biopolymer decreased permeability of the gaseous molecules. In summary, addition of halloysite nanoclay, improve the barrier and mechanical properties of potato starch films and this bionanocomposites have high potential to be used for food packaging purposes. Copyright © 2014 Elsevier B.V. All rights reserved.

  5. Development and characterization of a new bio-nanocomposite (bio-NCP) for diagnosis and treatment of breast cancer

    DEFF Research Database (Denmark)

    Martins, Murillo L; Saeki, Margarida J.; Telling, Mark T. F.

    2014-01-01

    Breast cancer is a public health problem throughout the world. Moreover, breast cancer cells have a great affinity for hydroxyapatite, leading to a high occurrence of bone metastasis. In this work we developed a bio-nanocomposite (bio-NCP) in order to use such affinity in the diagnosis...

  6. Stiffening mechanisms in amorphous polyamide bio-nanocomposites

    Energy Technology Data Exchange (ETDEWEB)

    Focke, Walter W. [Institute of Applied Materials, Department of Chemical Engineering, University of Pretoria, Private Bag X20, Hatfield 0028, Pretoria (South Africa); Macheca, Afonso D. [Institute of Applied Materials, Department of Chemical Engineering, University of Pretoria, Private Bag X20, Hatfield 0028, Pretoria (South Africa); Department of Chemical Engineering, Eduardo Mondlane University, P.O. Box 257, Maputo (Mozambique); Benhamida, Aida; Kaci, Mustapha [Laboratoire des Matériaux Polymères Avancés (LMPA), Université de Bejaia 06000 (Algeria)

    2016-05-18

    Dimer fatty acid polyamide nanocomposites based on flake- or needle-shaped nanoparticles were prepared via melt compounding. Transmission electron microscopy showed the presence of both individually dispersed particles and particle agglomerates in the polymer matrix. Dynamic mechanical analysis suggests that three stiffening mechanisms were operating. The reinforcing effect of the high stiffness inorganic filler particles is the primary contributor. Together with the chain confinement effect, that expresses itself in an apparent increase in the glass transition temperature, this provided an adequate rationalization of the stiffness variation below Tg. However, an additional stiffening effect is indicated at temperatures above Tg. The mechanism may involve dynamic network formation based on fluctuating hydrogen bonding interactions between the polymer chains and the filler particles.

  7. Binary PVA bio-nanocomposites containing cellulose nanocrystals extracted from different natural sources: part I.

    Science.gov (United States)

    Fortunati, E; Puglia, D; Luzi, F; Santulli, C; Kenny, J M; Torre, L

    2013-09-12

    PVA bio-nanocomposites reinforced with cellulose nanocrystals (CNC) extracted from commercial microcrystalline cellulose (MCC) and from two types of natural fibres, Phormium tenax and Flax of the Belinka variety, were produced by solvent casting in water. Morphological, thermal, mechanical and transparency properties were studied while the respective efficiency of the extraction process of CNC from the three sources was evaluated. The effect of CNC types and content on PVA properties and water absorption capacity were also evaluated. Natural fibres offered higher levels of extraction efficiency when compared with MCC hydrolysis yield. Thermal analysis proved that CNC promotes the crystallization of the PVA matrix, while improving its plastic response. It was also clarified that all PVA/CNC systems remain transparent due to CNC dispersion at the nanoscale, while being all saturated after the first 18-24h of water absorption. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. Improvement in Functional Properties of Soy Protein Isolate-Based Film by Cellulose Nanocrystal–Graphene Artificial Nacre Nanocomposite

    Directory of Open Access Journals (Sweden)

    Kuang Li

    2017-07-01

    Full Text Available A facile, inexpensive, and green approach for the production of stable graphene dispersion was proposed in this study. We fabricated soy protein isolate (SPI-based nanocomposite films with the combination of 2D negative charged graphene and 1D positive charged polyethyleneimine (PEI-modified cellulose nanocrystals (CNC via a layer-by-layer assembly method. The morphologies and surface charges of graphene sheets and CNC segments were characterized by atomic force microscopy and Zeta potential measurements. The hydrogen bonds and multiple interface interactions between the filler and SPI matrix were analyzed by Attenuated Total Reflectance–Fourier Transform Infrared spectra and X-ray diffraction patterns. Scanning electron microscopy demonstrated the cross-linked and laminated structures in the fracture surface of the films. In comparison with the unmodified SPI film, the tensile strength and surface contact angles of the SPI/graphene/PEI-CNC film were significantly improved, by 99.73% and 37.13% respectively. The UV–visible light barrier ability, water resistance, and thermal stability were also obviously enhanced. With these improved functional properties, this novel bio-nanocomposite film showed considerable potential for application for food packaging materials.

  9. TiO₂ (rutile) embedded inulin--A versatile bio-nanocomposite for photocatalytic degradation of methylene blue.

    Science.gov (United States)

    Jayanthi Kalaivani, G; Suja, S K

    2016-06-05

    Inulin, a water soluble carbohydrate polymer, was extracted from Allium sativum L. by hot water diffusion method. A novel bio-nanocomposite was prepared by embedding TiO2 (rutile) onto the inulin matrix. The extracted inulin and the prepared bio-nanocomposite were characterized using UV-vis, FT-IR, XRD, SEM, TEM and TGA techniques. The photocatalytic activity of the bio-nanocomposite for the degradation of methylene blue was studied under UV illumination in batch mode experiment and was found to be twice as high as that of pristine TiO2. The kapp for inulin-TiO2 (0.0449 min(-1)) was higher than that for TiO2 (0.0325 min(-1)) which may be due to the synergistic action of inulin and TiO2. The stabilization of photo excited electron suppressed the electron-hole pair recombination thereby inducing the electrons and the holes to participate in the photo reduction and oxidation processes, respectively and enhancing the photocatalytic activity. Copyright © 2016 Elsevier Ltd. All rights reserved.

  10. 3D TEM reconstruction and segmentation process of laminar bio-nanocomposites

    International Nuclear Information System (INIS)

    Iturrondobeitia, M.; Okariz, A.; Fernandez-Martinez, R.; Jimbert, P.; Guraya, T.; Ibarretxe, J.

    2015-01-01

    The microstructure of laminar bio-nanocomposites (Poly (lactic acid)(PLA)/clay) depends on the amount of clay platelet opening after integration with the polymer matrix and determines the final properties of the material. Transmission electron microscopy (TEM) technique is the only one that can provide a direct observation of the layer dispersion and the degree of exfoliation. However, the orientation of the clay platelets, which affects the final properties, is practically immeasurable from a single 2D TEM image. This issue can be overcome using transmission electron tomography (ET), a technique that allows the complete 3D characterization of the structure, including the measurement of the orientation of clay platelets, their morphology and their 3D distribution. ET involves a 3D reconstruction of the study volume and a subsequent segmentation of the study object. Currently, accurate segmentation is performed manually, which is inefficient and tedious. The aim of this work is to propose an objective/automated segmentation methodology process of a 3D TEM tomography reconstruction. In this method the segmentation threshold is optimized by minimizing the variation of the dimensions of the segmented objects and matching the segmented V clay (%) and the actual one. The method is first validated using a fictitious set of objects, and then applied on a nanocomposite

  11. Development and characterization of a new bio-nanocomposite (bio-NCP) for diagnosis and treatment of breast cancer

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Murillo L., E-mail: murillolongo@gmail.com [Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen (Denmark); Instituto de Biociências – Universidade Estadual Paulista – CP 510, 18618-970 Botucatu, SP (Brazil); Saeki, Margarida Juri [Instituto de Biociências – Universidade Estadual Paulista – CP 510, 18618-970 Botucatu, SP (Brazil); Telling, Mark T.F. [ISIS, Rutherford Appleton Laboratory, Chilton, Didcot OX11 OQX (United Kingdom); Department of Materials, University of Oxford, Parks Road, Oxford (United Kingdom); Parra, Joao P.R.L.L. [Instituto de Biociências – Universidade Estadual Paulista – CP 510, 18618-970 Botucatu, SP (Brazil); Landsgesell, Sven [Helmholtz–Zentrum Berlin für Materialien und Energie, Hahn-Meitner Platz 1, D-14109 Berlin (Germany); Smith, Ron I. [ISIS, Rutherford Appleton Laboratory, Chilton, Didcot OX11 OQX (United Kingdom); Bordallo, Heloisa N. [Niels Bohr Institute, University of Copenhagen, DK-2100 Copenhagen (Denmark)

    2014-01-25

    Highlights: • We synthesized a magnetic bio-NCP with potential to be used against breast cancer. • The magnetic nanoparticles have an inverted spinel structure. • The coating with chitosan does not cause changes to the particle microstructure. • The hydration level of bio-NCP is crucial to the surface modification with apatite. • Bio-NCP with narrow size distribution and high magnetic response was obtained. -- Abstract: Breast cancer is a public health problem throughout the world. Moreover, breast cancer cells have a great affinity for hydroxyapatite, leading to a high occurrence of bone metastasis. In this work we developed a bio-nanocomposite (bio-NCP) in order to use such affinity in the diagnosis and treatment of breast cancer. The bio-NCP consists of magnetic nanoparticles of Mn and Zn ferrite inside a polymeric coating (chitosan) modified with nanocrystals of apatite. The materials were characterized with synchrotron X-ray Powder Diffraction (XPD), Time-of-Flight Neutron Powder Diffraction (NPD), Fourier Transformed Infra-red Spectroscopy (FTIR), Scanning Electron Microscopy (SEM) and magnetic measurement with a Physical Property Measurement System (PPMS). We obtained ferrite nanoparticles with a high inversion degree of the spinel structure regarding the Fe and Mn, but with all the Zn in the A site. The coating of such nanoparticles with chitosan had no notable effects to the ferrite microstructure. In addition, the polymeric surface can be easily modified with apatite nanocrystals since the hydration of the bio-NCP during synthesis can be controlled. The resulting bio-NCP presents a spherical shape with a narrow size distribution and high magnetic response at room temperature and is a very promising material for early diagnosis of breast cancer and its treatment.

  12. Mechanical and morphological characterization of a bio-nanocomposite hydroxyapatite / polyurethane

    International Nuclear Information System (INIS)

    Andrade, Sabina da Memoria Cardoso de; Dias, Carmen Gilda Barroso Tavares; Zavaglia, Cecilia Amelia de Carvalho

    2011-01-01

    Nanocomposites based on biocompatible polymers and hydroxyapatite are wide acceptance as bone grafts, the composition, structure and similarity to natural bone and also due to the properties functional, such as surface and mechanical strength. This work there was the making of a bionanocomposite, using nanostructured hydroxyapatite interconnected by polyurethane, generated from the actions of poly(vinylalcohol) and toluene isocyanate HDT. The formation kinetics was monitored by the bionanocomposite spectroscopy and Fourier transform infrared FTIR. The material showed good properties both mechanical and morphology. (author)

  13. Characterization of the new biodegradable WPI/clay nanocomposite films based on kefiran exopolysaccharide.

    Science.gov (United States)

    Zolfi, Mohsen; Khodaiyan, Faramarz; Mousavi, Mohammad; Hashemi, Maryam

    2015-06-01

    Physico-mechanical, thermal and structural characteristics of nanocomposite film composed of kefiran-whey protein isolate (WPI)-montmorillonite (MMT; 1, 3 and 5 % w/w) were studied. Incorporation of MMT significantly affected the mechanical attributes of the kefiran-WPI films. The tensile strength and Young's modulus increased and the percentage of elongation at break decreased as the MMT content increased. Moisture content, moisture absorption and water solubility decreased as the MMT concentration increased. Differential scanning calorimetry indicated that the glass transition temperature for kefiran-WPI film was -12.5 °C and was noticeably affected by an increase in MMT. X-ray diffraction analysis showed formation of an exfoliated structure with the addition of small amounts of MMT to the kefiran-WPI matrix. Intercalation and some exfoliation occurred up to 5 % (wt) increase in MMT. Scanning electron microscopy demonstrated ideal dispersion for MMT nanoparticles into the structure of the bio-nanocomposite films.

  14. Structure and sorption properties of CNC reinforced PVA films.

    Science.gov (United States)

    Popescu, Maria-Cristina

    2017-08-01

    Bio-nanocomposite films based on cellulose nanocrystals reinforced poly(vinyl alcohol) were obtained by solvent casting method. To assess the structural features of the films, different spectral techniques (FTIR, 2D COS and XRD) have been used. Infrared and 2D correlation spectroscopy evidenced the presence of H-bond interactions between the PVA and CNC, and the variation in the conformational rearrangements, while XRD showed that the crystallite size and the crystallinity degree were affected by the incorporation of CNC. At low content of CNC in the PVA matrix, the crystallinity degree decreased to 29.9%, while at higher CNC content increased to 80.6%, comparing to PVA (35.4%). To evaluate the interaction with water, contact angle measurement, water sorption and NIR spectroscopy were used, respectively. The increase of the CNC content induced a reduction in water sorption ability from 93% for PVA to 75% for PVA/CNC films, indicating the involvement of the hydroxyl groups in new hydrogen bonded interactions. By analyzing the variation of the NIR bands from 1930, 1902 and 1985nm, was observed that the water molecules interact with the polymer matrix through moderate hydrogen bond before diffusing into the free volume of the matrix and form stronger hydrogen bonds. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. PVA-based nanographene film by electrospinning

    Directory of Open Access Journals (Sweden)

    Pang Jing

    2013-01-01

    Full Text Available Two-dimensional polyvinyl alcohol based graphene films with the thickness of less than 20 nm were fabricated directly by using polyvinyl alcohol/graphite solution or polyvinyl alcohol/ash solution by electrospinning. It was found that ash particles are good candidate for substitution of graphite particles to fabricate nanographene films. The relationship between the thickness and width of the film is elucidated, and the periodic morphology of the film is explained.

  16. Film Analysis through Linguistic Base

    Science.gov (United States)

    Tanriverdi, Belgin

    2007-01-01

    Studies made in the last few years show that using films in language classrooms is an effective way in teaching a foreign language. Well-chosen films can serve as a valuable pedagogical aid, both for classroom use and self-study. This article is about using films in language classrooms through a specially designed course, whose outline description…

  17. Novel fungus-Fe{sub 3}O{sub 4} bio-nanocomposites as high performance adsorbents for the removal of radionuclides

    Energy Technology Data Exchange (ETDEWEB)

    Ding, Congcong [Institute of Plasma Physics, Chinese Academy of Science, P.O. Box 1126, Hefei 230031 (China); University of Science and Technology of China, Hefei 230000 (China); Cheng, Wencai [Institute of Plasma Physics, Chinese Academy of Science, P.O. Box 1126, Hefei 230031 (China); Sun, Yubing, E-mail: sunyb@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Science, P.O. Box 1126, Hefei 230031 (China); School for Radiological and Interdisciplinary Sciences (RAD-X), Soochow University and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, 215123 Suzhou (China); School of Environment and Chemical Engineering, North China Electric Power University, Beijing 102206 (China); Wang, Xiangke, E-mail: xkwang@ipp.ac.cn [Institute of Plasma Physics, Chinese Academy of Science, P.O. Box 1126, Hefei 230031 (China); School for Radiological and Interdisciplinary Sciences (RAD-X), Soochow University and Collaborative Innovation Center of Radiation Medicine of Jiangsu Higher Education Institutions, 215123 Suzhou (China); School of Environment and Chemical Engineering, North China Electric Power University, Beijing 102206 (China); Faculty of Engineering, King Abdulaziz University, Jeddah 21589 (Saudi Arabia)

    2015-09-15

    Highlights: • Fungus was used as a template for the assembly of nano-Fe{sub 3}O{sub 4}. • Fungal template directed the nano-Fe{sub 3}O{sub 4} structure from the micro-scale level. • Fungal template enhanced the dispersity and stability of nano-Fe{sub 3}O{sub 4}. • Fungus-Fe{sub 3}O{sub 4} exhibited high sorption capacity for Sr(II), Th(IV) and U(VI). • Fungus-Fe{sub 3}O{sub 4} possessed satisfactory regeneration performance and reusability. - Abstract: The bio-nanocomposites of fungus-Fe{sub 3}O{sub 4} were successfully synthesized using a low-cost self-assembly technique. SEM images showed uniform decoration of nano-Fe{sub 3}O{sub 4} particles on fungus surface. The FTIR analysis indicated that nano-Fe{sub 3}O{sub 4} was combined to the fungus surface by chemical bonds. The sorption ability of fungus-Fe{sub 3}O{sub 4} toward Sr(II), Th(IV) and U(VI) was evaluated by batch techniques. Radionuclide sorption on fungus-Fe{sub 3}O{sub 4} was independent of ionic strength, indicating that inner-sphere surface complexion dominated their sorption. XPS analysis indicated that the inner-sphere radionuclide complexes were formed by mainly bonding with oxygen-containing functional groups (i.e., alcohol, acetal and carboxyl) of fungus-Fe{sub 3}O{sub 4}. The maximum sorption capacities of fungus-Fe{sub 3}O{sub 4} calculated from Langmuir isotherm model were 100.9, 223.9 and 280.8 mg/g for Sr(II) and U(VI) at pH 5.0, and Th(IV) at pH 3.0, respectively, at 303 K. Fungus-Fe{sub 3}O{sub 4} also exhibited excellent regeneration performance for the preconcentration of radionuclides. The calculated thermodynamic parameters showed that the sorption of radionuclides on fungus-Fe{sub 3}O{sub 4} was a spontaneous and endothermic process. The findings herein highlight the novel synthesis method of fungus-Fe{sub 3}O{sub 4} and its high sorption ability for radionuclides.

  18. Biosensors Based on Ultrathin Film Composite Membranes

    Science.gov (United States)

    1994-01-25

    composite membranes should have a number C •’ of potential advantages including fast response time, simplicity of construction, and applicability to a number...The support membrane for the ultrathin film composite was an Anopore ( Alltech Associates) microporous alumina filter, these membranes are 55 Pm thick...constant 02 concentration in this solution. Finally, one of the most important potential advantage of a sensor based on an ultrathin film composite

  19. A REVIEW ON BIODEGRADABLE STARCH BASED FILM

    Directory of Open Access Journals (Sweden)

    Hooman Molavi

    2015-04-01

    Full Text Available In recent years, biodegradable edible films have become very important in research related to food, due to their compatibility with the environment and their use in the food packaging industry. Various sources can be used in the production of biopolymers as biodegradable films that include polysaccharides, proteins and lipids. Among the various polysaccharides, starch due to its low price and its abundance in nature is of significant importance. Several factors affect the properties of starch films; such as the source which starch is obtained from, as well as the ratio of constituents of the starch. Starch films have advantages such as low thickness, flexibility and transparency though; there are some downsides to mention, such as the poor mechanical properties and water vapor permeability. Thus, using starch alone to produce the film will led to restrictions on its use. To improve the mechanical properties of starch films and also increases resistance against humidity, several methods can be used; including the starch modifying techniques such as cross linking of starch and combining starch with other natural polymers. Other methods such as the use of lipid in formulations of films to increase the resistance to moisture are possible, but lipids are susceptible to oxidation. Therefore, new approaches are based on the integration of different biopolymers in food packaging.

  20. Well-dispersed cellulose nanocrystals in hydrophobic polymers by in situ polymerization for synthesizing highly reinforced bio-nanocomposites.

    Science.gov (United States)

    Geng, Shiyu; Wei, Jiayuan; Aitomäki, Yvonne; Noël, Maxime; Oksman, Kristiina

    2018-04-20

    In nanocomposites, dispersing hydrophilic nanomaterials in a hydrophobic matrix using simple and environmentally friendly methods remains challenging. Herein, we report a method based on in situ polymerization to synthesize nanocomposites of well-dispersed cellulose nanocrystals (CNCs) and poly(vinyl acetate) (PVAc). We have also shown that by blending this PVAc/CNC nanocomposite with poly(lactic acid) (PLA), a good dispersion of the CNCs can be reached in PLA. The outstanding dispersion of CNCs in both PVAc and PLA/PVAc matrices was shown by different microscopy techniques and was further supported by the mechanical and rheological properties of the composites. The in situ PVAc/CNC nanocomposites exhibit enhanced mechanical properties compared to the materials produced by mechanical mixing, and a theoretical model based on the interphase effect and dispersion that reflects this behavior was developed. Comparison of the rheological and thermal behaviors of the mixed and in situ PVAc/CNC also confirmed the great improvement in the dispersion of nanocellulose in the latter. Furthermore, a synergistic effect was observed with only 0.1 wt% CNCs when the in situ PVAc/CNC was blended with PLA, as demonstrated by significant increases in elastic modulus, yield strength, elongation to break and glass transition temperature compared to the PLA/PVAc only material.

  1. 49 CFR 173.183 - Nitrocellulose base film.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Nitrocellulose base film. 173.183 Section 173.183... Nitrocellulose base film. Films, nitrocellulose base, must be packaged in packagings conforming to the... tape or paper; authorized only for not over 600 m (1969 feet) of film. [Amdt. 173-224, 55 FR 52643 Dec...

  2. Fragrant starch-based films with limonene

    Directory of Open Access Journals (Sweden)

    Adrian K. Antosik

    2017-02-01

    Full Text Available Novel fragrant starch-based films with limonene were successfully prepared. Biodegradable materials of natural origin were used and the process was relatively simple and inexpensive. The effect of limonene on physicochemical properties of starch-based films (moisture absorption, solubility in water, wettability, mechanical properties were compared to glycerol plasticized system. Taking into consideration that the obtained materials could also exhibit bactericidal and fungicidal properties, the studies with Escherichia coli, Candida albicans and Aspergillus niger were performed. Such a material could potentially find application in food packaging (e.g. masking unpleasant odors, hydrophilic starch film would prevent food drying, or in agriculture (e.g. for seed encapsulated tapes.

  3. A PC based thin film dosimeter system

    DEFF Research Database (Denmark)

    Miller, A.; Hargittai, P.; Kovacs, A.

    2000-01-01

    A dosimeter system based on the Riso B3 dosimeter film, an office scanner for use with PC and the associated software is presented. The scanned image is analyzed either with standard software (Paint Shop Pro 5 or Excel) functions or with the computer code "Scanalizer" that allows presentation...

  4. Poly(Lactic Acid) Based Flexible Films

    OpenAIRE

    Fathilah binti Ali; Jamarosliza Jamaluddin; Arun Kumar Upadhyay

    2014-01-01

    Poly(lactic acid) (PLA) is a biodegradable polymer which has good mechanical properties, however, its brittleness limits its usage especially in packaging materials. Therefore, in this work, PLA based polyurethane films were prepared by synthesizing with different types of isocyanates; methylene diisocyanate (MDI) and hexamethylene diisocyanates (HDI). For this purpose, PLA based polyurethane must have good strength and flexibility. Therefore, polycaprolactone which has b...

  5. Film-thickness and composition dependence of epitaxial thin-film PZT-based

    NARCIS (Netherlands)

    Nguyen, Duc Minh; Dekkers, Jan M.; Vu, Hung Ngoc; Rijnders, Augustinus J.H.M.

    2013-01-01

    The transverse piezoelectric coefficient e31,f and mass-sensitivity were measured on piezoelectric cantilevers based on epitaxial PZT thin-films with film-thicknesses ranging from 100 to 2000 nm. The highest values of e31,f and mass-sensitivity were observed at a film thickness of 500–750 nm, while

  6. Emerging Chitosan-Based Films for Food Packaging Applications.

    Science.gov (United States)

    Wang, Hongxia; Qian, Jun; Ding, Fuyuan

    2018-01-17

    Recent years have witnessed great developments in biobased polymer packaging films for the serious environmental problems caused by the petroleum-based nonbiodegradable packaging materials. Chitosan is one of the most abundant biopolymers after cellulose. Chitosan-based materials have been widely applied in various fields for their biological and physical properties of biocompatibility, biodegradability, antimicrobial ability, and easy film forming ability. Different chitosan-based films have been fabricated and applied in the field of food packaging. Most of the review papers related to chitosan-based films are focusing on antibacterial food packaging films. Along with the advances in the nanotechnology and polymer science, numerous strategies, for instance direct casting, coating, dipping, layer-by-layer assembly, and extrusion, have been employed to prepare chitosan-based films with multiple functionalities. The emerging food packaging applications of chitosan-based films as antibacterial films, barrier films, and sensing films have achieved great developments. This article comprehensively reviews recent advances in the preparation and application of engineered chitosan-based films in food packaging fields.

  7. Functional properties of edible agar-based and starch-based films for food quality preservation.

    Science.gov (United States)

    Phan, The D; Debeaufort, F; Luu, D; Voilley, A

    2005-02-23

    Edible films made of agar (AG), cassava starch (CAS), normal rice starch (NRS), and waxy (glutinous) rice starch (WRS) were elaborated and tested for a potential use as edible packaging or coating. Their water vapor permeabilities (WVP) were comparable with those of most of the polysaccharide-based films and with some protein-based films. Depending on the environmental moisture pressure, the WVP of the films varies and remains constant when the relative humidity (RH) is >84%. Equilibrium sorption isotherms of these films have been measured; the Guggenheim-Anderson-de Boer (GAB) model was used to describe the sorption isotherm and contributed to a better knowledge of hydration properties. Surface hydrophobicity and wettability of these films were also investigated using the sessile drop contact angle method. The results obtained suggested the migration of the lipid fraction toward evaporation surface during film drying. Among these polysaccharide-based films, AG-based film and CAS-based film displayed more interesting mechanical properties: they are transparent, clear, homogeneous, flexible, and easily handled. NRS- and WRS-based films were relatively brittle and have a low tension resistance. Microstructure of film cross section was observed by environmental scanning electron microscopy to better understand the effect of the structure on the functional properties. The results suggest that AG-based film and CAS-based films, which show better functional properties, are promising systems to be used as food packaging or coating instead of NRS- and WRS-based films.

  8. Rare earth-based low-index films for IR and multispectral thin film solutions

    Science.gov (United States)

    Stolze, Markus; Neff, Joe; Waibel, Friedrich

    2017-10-01

    Non-thoriated rare-earth fluoride based coating solutions involving DyF3 and YbF3 based films as well as non-wetting fluorohydrocarbon cap layers on such films, have been deposited, analyzed and partly optimized. Intermediate results for DyF3 based films from ion assisted e-gun deposition with O2 and N2 alone and as base for the non-wetting to-player as well as for YbF3 starting material with or without admixtures of CaF2 are discussed for low-loss LWIR and multispectral solutions.

  9. Whey protein-based films incorporated with oregano essential oil

    Directory of Open Access Journals (Sweden)

    Sandra Prestes Lessa Fernandes Oliveira

    Full Text Available Abstract This study aimed to prepare whey protein-based films incorporated with oregano essential oil at different concentrations, and evaluate their properties and antimicrobial activity. Films were more flexible with increasing the concentration of oregano oil and water vapor permeability was higher in the films with oregano oil. Increasing the concentration of essential oil decreased the water solubility. The solubility of control film and film with 1.5% oregano oil was 20.2 and 14.0%, respectively. The addition of 1% of oregano oil improved the resistance of the films. The tensile strength for the control film was 66.0 MPa, while for the film with 1% of oregano oil was 108.7 MPa. Films containing 1.5% oregano oil showed higher antimicrobial activity. The zone of inhibition ranged from 0 to 1.7 cm. The results showed that the whey protein-based films incorporated with oregano essential oil has potential application as active packaging.

  10. Organic Photovoltaic Devices Based on Oriented n-Type Molecular Films Deposited on Oriented Polythiophene Films.

    Science.gov (United States)

    Mizokuro, Toshiko; Tanigaki, Nobutaka; Miyadera, Tetsuhiko; Shibata, Yousei; Koganezawa, Tomoyuki

    2018-04-01

    The molecular orientation of π-conjugated molecules has been reported to significantly affect the performance of organic photovoltaic devices (OPVs) based on molecular films. Hence, the control of molecular orientation is a key issue toward the improvement of OPV performance. In this research, oriented thin films of an n-type molecule, 3,4,9,10-Perylenetetracarboxylic Bisbenzimida-zole (PTCBI), were formed by deposition on in-plane oriented polythiophene (PT) films. Orientation of the PTCBI films was evaluated by polarized UV-vis spectroscopy and 2D-Grazing incidence X-ray diffraction. Results indicated that PTCBI molecules on PT film exhibit nearly edge-on and in-plane orientation (with molecular long axis along the substrate), whereas PTCBI molecules without PT film exhibit neither. OPVs composed of PTCBI molecular film with and without PT were fabricated and evaluated for correlation of orientation with performance. The OPVs composed of PTCBI film with PT showed higher power conversion efficiency (PCE) than that of film without PT. The experiment indicated that in-plane orientation of PTCBI molecules absorbs incident light more efficiently, leading to increase in PCE.

  11. Ion beam-based characterization of multicomponent oxide thin films and thin film layered structures

    International Nuclear Information System (INIS)

    Krauss, A.R.; Rangaswamy, M.; Lin, Yuping; Gruen, D.M.; Schultz, J.A.; Schmidt, H.K.; Chang, R.P.H.

    1992-01-01

    Fabrication of thin film layered structures of multi-component materials such as high temperature superconductors, ferroelectric and electro-optic materials, and alloy semiconductors, and the development of hybrid materials requires understanding of film growth and interface properties. For High Temperature Superconductors, the superconducting coherence length is extremely short (5--15 Angstrom), and fabrication of reliable devices will require control of film properties at extremely sharp interfaces; it will be necessary to verify the integrity of thin layers and layered structure devices over thicknesses comparable to the atomic layer spacing. Analytical techniques which probe the first 1--2 atomic layers are therefore necessary for in-situ characterization of relevant thin film growth processes. However, most surface-analytical techniques are sensitive to a region within 10--40 Angstrom of the surface and are physically incompatible with thin film deposition and are typically restricted to ultra high vacuum conditions. A review of ion beam-based analytical methods for the characterization of thin film and multi-layered thin film structures incorporating layers of multicomponent oxides is presented. Particular attention will be paid to the use of time-of-flight techniques based on the use of 1- 15 key ion beams which show potential for use as nondestructive, real-time, in-situ surface diagnostics for the growth of multicomponent metal and metal oxide thin films

  12. Moisture Absorption Behaviour of Biopolymer Polycapralactone (PCL) / Organo Modified Montmorillonite Clay (OMMT) biocomposite films

    Science.gov (United States)

    Malik, Neetu; Shrivastava, Sharad; Bandhu Ghosh, Subrata

    2018-04-01

    Bio composite materials were fabricated using mixing biodegradable polymer polycaptalactone (PCL) and Organo Modified Montmorillonite Clay (OMMT) through solution casting. Various samples of bio composite films were prepared by varying the OMMT wt% composition by 0.1%, 0.5%, 1% and 1.5%. Thereafter, the density and water absorption of the composites were investigated with respect to immersion time in water. The moisture absorption results show that with an increase in weight percentage (from 0.1 to wt 1.5%) of OMMT within the bio polymer films, the absorption value of bio-nanocomposite films reduced rapidly from 34.4% to 22.3%. The density of hybrid composites also increased with increase in weight percentage of OMMT. The swelling characteristic of PCL increased with increasing % of OMMT clay. These results indicate that the optimized composition of constituents in composite membrane could effectively reduce the anhydrous conditions of bio-composite film.

  13. Film-based dual energy radiography

    International Nuclear Information System (INIS)

    Sandrik, J. M.; Pelc, N. J.

    1985-01-01

    X-ray energy-difference images are obtained simultaneously by exposing a body to a broad energy spectrum X-ray beam while a radiographic film package is disposed between front and rear X-ray intensifying screens. The film package has two superimposed films with a light-opaque sheet between them. The front screen, on which the polyenergetic image beam emerging from the body is incident, is excited to luminescence by X-ray photons predominantly in one energy band and the rear screen is excited predominantly by photons in another band. The light opaque sheet preferably contains X-ray filter material for additional filtering of photons to increase the fraction of protons at said other band to which the rear screen is sensitive. A shadowgraph of a marker is formed on the film emulsions during X-ray exposure to aid in matching congruent picture elements on each film when the developed films are being read out to obtain signals corresponding to their intensities. Notches in the edges of the films and sheet serve as a code for indicating the type of screens with which the package can be used

  14. Humidity detection using chitosan film based sensor

    Science.gov (United States)

    Nasution, T. I.; Nainggolan, I.; Dalimunthe, D.; Balyan, M.; Cuana, R.; Khanifah, S.

    2018-02-01

    A humidity sensor made of the natural polymer chitosan has been successfully fabricated in the film form by a solution casting method. Humidity testing was performed by placing a chitosan film sensor in a cooling machine room, model KT-2000 Ahu. The testing results showed that the output voltage values of chitosan film sensor increased with the increase in humidity percentage. For the increase in humidity percentage from 30 to 90% showed that the output voltage of chitosan film sensor increased from 32.19 to 138.75 mV. It was also found that the sensor evidenced good repeatability and stability during the testing. Therefore, chitosan has a great potential to be used as new sensing material for the humidity detection of which was cheaper and environmentally friendly.

  15. Antimicrobial nanostructured starch based films for packaging.

    Science.gov (United States)

    Abreu, Ana S; Oliveira, M; de Sá, Arsénio; Rodrigues, Rui M; Cerqueira, Miguel A; Vicente, António A; Machado, A V

    2015-09-20

    Montmorillonite modified with a quaternary ammonium salt C30B/starch nanocomposite (C30B/ST-NC), silver nanoparticles/starch nanocomposite (Ag-NPs/ST-NC) and both silver nanoparticles/C30B/starch nanocomposites (Ag-NPs/C30B/ST-NC) films were produced. The nanoclay (C30B) was dispersed in a starch solution using an ultrasonic probe. Different concentrations of Ag-NPs (0.3, 0.5, 0.8 and 1.0mM) were synthesized directly in starch and in clay/starch solutions via chemical reduction method. Dispersion of C30B silicate layers and Ag-NPs in ST films characterized by X-ray and scanning electron microscopy showed that the presence of Ag-NPs enhanced clay dispersion. Color and opacity measurements, barrier properties (water vapor and oxygen permeabilities), dynamic mechanical analysis and contact angle were evaluated and related with the incorporation of C30B and Ag-NPs. Films presented antimicrobial activity against Staphylococcus aureus, Escherichia coli and Candida albicans without significant differences between Ag-NPs concentrations. The migration of components from the nanostructured starch films, assessed by food contact tests, was minor and under the legal limits. These results indicated that the starch films incorporated with C30B and Ag-NPs have potential to be used as packaging nanostructured material. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Supercapacitors based on flexible graphene/polyaniline nanofiber composite films.

    Science.gov (United States)

    Wu, Qiong; Xu, Yuxi; Yao, Zhiyi; Liu, Anran; Shi, Gaoquan

    2010-04-27

    Composite films of chemically converted graphene (CCG) and polyaniline nanofibers (PANI-NFs) were prepared by vacuum filtration the mixed dispersions of both components. The composite film has a layered structure, and PANI-NFs are sandwiched between CCG layers. Furthermore, it is mechanically stable and has a high flexibility; thus, it can be bent into large angles or be shaped into various desired structures. The conductivity of the composite film containing 44% CCG (5.5 x 10(2) S m(-1)) is about 10 times that of a PANI-NF film. Supercapacitor devices based on this conductive flexible composite film showed large electrochemical capacitance (210 F g(-1)) at a discharge rate of 0.3 A g(-1). They also exhibited greatly improved electrochemical stability and rate performances.

  17. Aroma barrier properties of sodium caseinate-based films.

    Science.gov (United States)

    Fabra, Maria José; Hambleton, Alicia; Talens, Pau; Debeaufort, Fréderic; Chiralt, Amparo; Voilley, Andrée

    2008-05-01

    The mass transport of six different aroma compounds (ethyl acetate, ethyl butyrate, ethyl hexanoate, 2-hexanone, 1-hexanol, and cis-3-hexenol) through sodium caseinate-based films with different oleic acid (OA)/beeswax (BW) ratio has been studied. OA is less efficient than BW in reducing aroma permeability, which can be attributed to its greater polarity. Control film (without lipid) and films prepared with 0:100 OA/BW ratio show the lowest permeability. OA involves a decrease in aroma barrier properties of the sodium caseinate-based films due to its plasticization ability. Preferential sorption and diffusion occurs through OA instead of caseinate matrix and/or BW. The efficiency of sodium caseinate-based films to retain or limit aroma compound transfers depend on the affinity of the volatile compound to the films, which relates physicochemical interaction between volatile compound and film. Specific interactions (aroma compound-hydrocolloid and aroma compound-lipid) induce structural changes during mass transfer.

  18. Thermoforming of film-based biomedical microdevices

    NARCIS (Netherlands)

    Truckenmüller, R.K.; Giselbrecht, Stefan; Rivron, N.C.; Gottwald, Eric; Saile, Volker; van den Berg, Albert; Wessling, Matthias; van Blitterswijk, Clemens

    2011-01-01

    For roughly ten years now, a new class of polymer micromoulding processes comes more and more into the focus both of the microtechnology and the biomedical engineering community. These processes can be subsumed under the term "microthermoforming". In microthermoforming, thin polymer films are heated

  19. Conducting polymer-based multilayer films for instructive biomaterial coatings

    OpenAIRE

    Hardy, John G; Li, Hetian; Chow, Jacqueline K; Geissler, Sydney A; McElroy, Austin B; Nguy, Lindsey; Hernandez, Derek S; Schmidt, Christine E

    2015-01-01

    Aim: To demonstrate the design, fabrication and testing of conformable conducting biomaterials that encourage cell alignment. Materials & methods: Thin conducting composite biomaterials based on multilayer films of poly (3,4-ethylenedioxythiophene) derivatives, chitosan and gelatin were prepared in a layer-by-layer fashion. Fibroblasts were observed with fluorescence microscopy and their alignment (relative to the dipping direction and direction of electrical current passed through the films)...

  20. Thin film ionic conductors based on cerium oxide

    International Nuclear Information System (INIS)

    Haridoss, P.; Hellstrom, E.; Garzon, F.H.; Brown, D.R.; Hawley, M.

    1994-01-01

    Fluorite and perovskite structure cerium oxide based ceramics are a class of materials that may exhibit good oxygen ion and/or protonic conductivity. The authors have successfully deposited thin films of these materials on a variety of substrates. Interesting orientation relationships were noticed between cerium oxide films and strontium titanate bi-crystal substrates. Near lattice site coincidence theory has been used to study these relationships

  1. Nanoparticles doped film sensing based on terahertz metamaterials

    Science.gov (United States)

    Liu, Weimin; Fan, Fei; Chang, Shengjiang; Hou, Jiaqing; Chen, Meng; Wang, Xianghui; Bai, Jinjun

    2017-12-01

    A nanoparticles concentration sensor based on doped film and terahertz (THz) metamaterial has been proposed. By coating the nanoparticles doped polyvinyl alcohol (PVA) film on the surface of THz metamaterial, the effects of nanoparticle concentration on the metamaterial resonances are investigated through experiments and numerical simulations. Results show that resonant frequency of the metamaterial linearly decreases with the increment of doping concentration. Furthermore, numerical simulations illustrate that the redshift of resonance results from the changes of refractive index of the doped film. The concentration sensitivity of this sensor is 3.12 GHz/0.1%, and the refractive index sensitivity reaches 53.33 GHz/RIU. This work provides a non-contact, nondestructive and sensitive method for the detection of nanoparticles concentration and brings out a new application on THz film metamaterial sensing.

  2. MEMS-based thick film PZT vibrational energy harvester

    DEFF Research Database (Denmark)

    Lei, Anders; Xu, Ruichao; Thyssen, Anders

    2011-01-01

    We present a MEMS-based unimorph silicon/PZT thick film vibrational energy harvester with an integrated proof mass. We have developed a process that allows fabrication of high performance silicon based energy harvesters with a yield higher than 90%. The process comprises a KOH etch using a mechan......We present a MEMS-based unimorph silicon/PZT thick film vibrational energy harvester with an integrated proof mass. We have developed a process that allows fabrication of high performance silicon based energy harvesters with a yield higher than 90%. The process comprises a KOH etch using...... a mechanical front side protection of an SOI wafer with screen printed PZT thick film. The fabricated harvester device produces 14.0 μW with an optimal resistive load of 100 kΩ from 1g (g=9.81 m s-2) input acceleration at its resonant frequency of 235 Hz....

  3. Development and Evaluation of Cefadroxil Drug Loaded Biopolymeric Films Based on Chitosan-Furfural Schiff Base

    Science.gov (United States)

    Dixit, Ritu B.; Uplana, Rahul A.; Patel, Vishnu A.; Dixit, Bharat C.; Patel, Tarosh S.

    2010-01-01

    Cefadroxil drug loaded biopolymeric films of chitosan-furfural schiff base were prepared by reacting chitosan with furfural in presence of acetic acid and perchloric acid respectively for the external use. Prepared films were evaluated for their strength, swelling index, thickness, drug content, uniformity, tensile strength, percent elongation, FTIR spectral analysis and SEM. The results of in vitro diffusion studies revealed that the films exhibited enhanced drug diffusion as compared to the films prepared using untreated chitosan. The films also demonstrated good to moderate antibacterial activities against selective gram positive and gram negative bacteria. PMID:21179325

  4. Mechanical and morphological characterization of a bio-nanocomposite hydroxyapatite / polyurethane; Caracterizacao mecanica e morfologica de um bionanocomposito hidroxiapatita/poliuretano

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Sabina da Memoria Cardoso de, E-mail: sabina_memoria@yahoo.com.br [Instituto Federal de Educacao Ciencia e Tecnologia do Para (IFPA), Belem, PA (Brazil); Dias, Carmen Gilda Barroso Tavares [Universidade Federal do Para (UFPA), Belem, PA (Brazil). Departamento de Engenharia Mecanica; Zavaglia, Cecilia Amelia de Carvalho [Universidade Estadual de Campinas (UNICAMP), SP (Brazil). Departamento de Engenharia Mecanica

    2011-07-01

    Nanocomposites based on biocompatible polymers and hydroxyapatite are wide acceptance as bone grafts, the composition, structure and similarity to natural bone and also due to the properties functional, such as surface and mechanical strength. This work there was the making of a bionanocomposite, using nanostructured hydroxyapatite interconnected by polyurethane, generated from the actions of poly(vinylalcohol) and toluene isocyanate HDT. The formation kinetics was monitored by the bionanocomposite spectroscopy and Fourier transform infrared FTIR. The material showed good properties both mechanical and morphology. (author)

  5. SUBTLEX-ESP: Spanish Word Frequencies Based on Film Subtitles

    Science.gov (United States)

    Cuetos, Fernando; Glez-Nosti, Maria; Barbon, Analia; Brysbaert, Marc

    2011-01-01

    Recent studies have shown that word frequency estimates obtained from films and television subtitles are better to predict performance in word recognition experiments than the traditional word frequency estimates based on books and newspapers. In this study, we present a subtitle-based word frequency list for Spanish, one of the most widely spoken…

  6. A Study Of Magnetic Fluid Based Squeeze Film Between Porous ...

    African Journals Online (AJOL)

    Efforts have been made to study and analyze the effect of surface roughness on the performance of magnetic fluid based squeeze film between porous elliptic plates. The transverse roughness of the bearing surface is characterized by a stochastic random variable with non-zero mean, variance and skewness.

  7. Grid-based Simulation of Industrial Thin Film Production

    NARCIS (Netherlands)

    Krzhizhanovskaya, V.V.; Sloot, P.M.A.; Gorbachev, Y.E.

    2005-01-01

    In this article, the authors introduce a Grid-based virtual reactor, a High Level Architecture (HLA)-supported problem-solving environment that allows for detailed numerical study of industrial thin-film production in plasma-enhanced chemical vapor deposition (PECVD) reactors. They briefly describe

  8. Study on Biodegradation of Palm Oil-based UV-Curable Films in Soil

    International Nuclear Information System (INIS)

    Rida Tajau; Siti Farhana Fathy; Mohamad Norahiman Abdurahman; Anis Asmi Azman; Nur Amira Hamidi; Mek Zah Salleh; Nik Ghazali Nik Salleh

    2014-01-01

    The palm oil-based ultraviolet (UV)-curable films were subjected to an outdoor soil burial test to investigate the biodegradation under natural environment. The films were burial in the soil experiment plot at the Nuclear Malaysia's Dengkil complex which is near the BTS building at block 42. Biodegradation tests are more specific to burial film in soil experiments for 12 months under natural conditions. The biodegradability of palm oil resin based UV-curable films were investigated and compared with the petrochemical resin based film. The films properties were compared with respect to properties of the film morphology and the film weight loss which are analyzed using the scanning electron microscope (SEM), an optical microscope and the weight loss of film calculation. These findings suggested that the palm oil-based UV-curable films show quite satisfactory biodegradation levels. (author)

  9. Fabrication of polypeptide-based piezoelectric composite polymer film

    International Nuclear Information System (INIS)

    Farrar, Dawnielle; West, James E.; Busch-Vishniac, Ilene J.; Yu, Seungju M.

    2008-01-01

    A new class of molecular composite piezoelectric material was produced by simultaneous poling and curing of a homogeneous solution comprising poly(γ-benzyl α,L-glutamate) and methylmethacrylate via corona discharge methods. This film exhibited high piezoelectricity (d 33 = 23 pC N -1 ), and its mechanical characteristics (modulus = 450 MPa) were similar to those of low molecular weight poly(methylmethacrylate). As it is produced via solution-based fabrication processes, the composite film is conducive to miniaturization for small sensors with integrated electronics, and could also potentially be used in piezoelectric coating applications

  10. A tunable hybrid metamaterial absorber based on vanadium oxide films

    International Nuclear Information System (INIS)

    Wen Qiye; Zhang Huaiwu; Yang Qinghui; Long Yang; Jing Yulan; Lin Yuan; Chen Zhi; Zhang Peixin

    2012-01-01

    A tunable hybrid metamaterial absorber (MA) in the microwave band was designed, fabricated and characterized. The hybrid MA was realized by incorporating a VO 2 film into the conventional resonant MA. By thermally triggering the insulator-metal phase transition of the VO 2 film, the impedance match condition was broken and a deep amplitude modulation of about 63.3% to the electromagnetic wave absorption was achieved. A moderate blue-shift of the resonance frequency was observed which is promising for practical applications. This VO 2 -based MA exhibits many advantages such as strong tunability, frequency agility, simple fabrication and ease of scaling to the terahertz band. (paper)

  11. Characterization of tellurium-based films for NO2 detection

    International Nuclear Information System (INIS)

    Tsiulyanu, D.; Tsiulyanu, A.; Liess, H.-D.; Eisele, I.

    2005-01-01

    Sensing characteristics of tellurium-based thin films for NO 2 monitoring was studied systematically. The influence of contact materials, thermal treatment, temperature and thickness of the samples on the electrical conductivity and sensitivity to NO 2 with respect to scanning electron microscopy analyses is given. The possibility is shown to optimize the properties of the films for the development of a simple and stable NO 2 sensor device with rapid response/recovery time and low operating temperature. The sensing mechanism is discussed for the direct interaction of gaseous species with lone-pair electrons of chalcogen atoms

  12. Mimetic marine antifouling films based on fluorine-containing polymethacrylates

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Qianhui [College of Chemistry, Chemical Engineering & Biotechnology, Donghua University, 2999 North Renmin Road, Shanghai 201620 (China); Li, Hongqi, E-mail: hongqili@dhu.edu.cn [College of Chemistry, Chemical Engineering & Biotechnology, Donghua University, 2999 North Renmin Road, Shanghai 201620 (China); Xian, Chunying; Yang, Yihang [College of Chemistry, Chemical Engineering & Biotechnology, Donghua University, 2999 North Renmin Road, Shanghai 201620 (China); Song, Yanxi [School of Environmental Science and Technology, Donghua University, 2999 North Renmin Road, Shanghai 201620 (China); State Key Laboratory of Molecular Engineering of Polymers, Fudan University, 220 Handan Road, Shanghai 200433 (China); Cong, Peihong [State Key Laboratory of Molecular Engineering of Polymers, Fudan University, 220 Handan Road, Shanghai 200433 (China)

    2015-07-30

    Graphical abstract: - Highlights: • Copolymers containing catechol and trifluoromethyl groups were prepared. • The copolymers could adhere to surfaces of glass, plastics and metals. • The polymer films showed excellent resistance to water, salt, base and acid. • The polymer films displayed good antifouling property. - Abstract: Novel methacrylate copolymers containing catechol and trifluoromethyl pendant side groups were synthesized by free radical polymerization of N-(3,4-dihydroxyphenyl)ethyl methacrylamide (DMA) and 2,2,2-trifluoroethyl methacrylate (TFME) with α,α′-azobisisobutyronitrile (AIBN) as initiator. A series of copolymers with different content of TFME ranging from 3% to 95% were obtained by changing the molar ratio of DMA to TFME from 25:1 to 1:25. Fourier transform infrared (FT-IR) spectroscopy, gel permeation chromatography (GPC), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) were used to characterize the copolymers, which displayed a certain degree of hardness and outstanding thermostability reflected from their high glass transition temperatures. The copolymers could adhere to surfaces of glass, plastics and metals due to introduction of catechol groups as multivalent hydrogen bonding anchors. Water contact angle on the polymer films was up to 117.4°. Chemicals resistance test manifested that the polymer films possessed excellent resistance to water, salt, acid and alkali. Moreover, the polymer films displayed fair antifouling property and might be used as promising environmentally friendly marine antifouling coatings.

  13. Mimetic marine antifouling films based on fluorine-containing polymethacrylates

    International Nuclear Information System (INIS)

    Sun, Qianhui; Li, Hongqi; Xian, Chunying; Yang, Yihang; Song, Yanxi; Cong, Peihong

    2015-01-01

    Graphical abstract: - Highlights: • Copolymers containing catechol and trifluoromethyl groups were prepared. • The copolymers could adhere to surfaces of glass, plastics and metals. • The polymer films showed excellent resistance to water, salt, base and acid. • The polymer films displayed good antifouling property. - Abstract: Novel methacrylate copolymers containing catechol and trifluoromethyl pendant side groups were synthesized by free radical polymerization of N-(3,4-dihydroxyphenyl)ethyl methacrylamide (DMA) and 2,2,2-trifluoroethyl methacrylate (TFME) with α,α′-azobisisobutyronitrile (AIBN) as initiator. A series of copolymers with different content of TFME ranging from 3% to 95% were obtained by changing the molar ratio of DMA to TFME from 25:1 to 1:25. Fourier transform infrared (FT-IR) spectroscopy, gel permeation chromatography (GPC), thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC) and scanning electron microscopy (SEM) were used to characterize the copolymers, which displayed a certain degree of hardness and outstanding thermostability reflected from their high glass transition temperatures. The copolymers could adhere to surfaces of glass, plastics and metals due to introduction of catechol groups as multivalent hydrogen bonding anchors. Water contact angle on the polymer films was up to 117.4°. Chemicals resistance test manifested that the polymer films possessed excellent resistance to water, salt, acid and alkali. Moreover, the polymer films displayed fair antifouling property and might be used as promising environmentally friendly marine antifouling coatings

  14. 36 CFR 1237.30 - How do agencies manage records on nitrocellulose-base and cellulose-acetate base film?

    Science.gov (United States)

    2010-07-01

    ... records on nitrocellulose-base and cellulose-acetate base film? 1237.30 Section 1237.30 Parks, Forests... and cellulose-acetate base film? (a) The nitrocellulose base, a substance akin to gun cotton, is chemically unstable and highly flammable. Agencies must handle nitrocellulose-base film (used in the...

  15. Graphene based humidity-insensitive films

    KAUST Repository

    Tai, Yanlong; Lubineau, Gilles

    2017-01-01

    A humidity nonsensitive material based on reduced-graphene oxide (r-GO) and methods of making the same are provided, in an embodiment, the materia! has a resistance/humidity variation of about -15% to 15% based on different sintering time

  16. Application of gamma irradiation on forming protein-based edible films; Aplicacao da irradiacao na formacao de filmes comestiveis proteicos

    Energy Technology Data Exchange (ETDEWEB)

    Sabato, Susy Frey

    2000-07-01

    In the last decade considerable interest has been addressed to the development of protein-based edible films due to their application in the food industry, as a substitute to traditional plastic films. The use of soy and whey proteins to form those films has been investigated, using heat, chemical and enzymatic processes. Gamma irradiation was recently reported to form caseinate-based edible films, due to the increase of the cohesive strength of the proteins by the formation of cross-links. This work aimed to verify the role of the gamma irradiation in the process of forming edible films from soy protein isolate (SPI) alone and in complex mixtures, that is, mixed with whey protein isolate (WPI), with carbethoxymethyl cellulose (CMC) and with poly(vinyl)alcohol (PVA). Gamma irradiation treatment improved significantly the mechanical properties for all films. The mechanical behavior is strongly related to the formulation, showing synergy between the gamma irradiation and the CMC, mainly for SPI-based films. SPI-based films presented a trend to decrease the water vapor permeability values when irradiated. The CMC addition showed significant improvements on the permeability for films from SPI and from the mixture of SPI with WPI. (author)

  17. Graphene based humidity-insensitive films

    KAUST Repository

    Tai, Yanlong

    2017-09-08

    A humidity nonsensitive material based on reduced-graphene oxide (r-GO) and methods of making the same are provided, in an embodiment, the materia! has a resistance/humidity variation of about -15% to 15% based on different sintering time or temperature. In an aspect, the resistance variation to humidity can be close to zero or -0.5% to 0.5%, showing a humidity non sensitivity property. In an embodiment, a humidity nonsensitive material based on the r-GO and carbon nanotube (CNT) composites is provided, wherein the ratio of CNT to r-GO is adjusted. The ratio can be adjusted based on the combined contribution of carbon nanotube (positive resistance variation) and reduced- graphene oxide (negative resistance variation) behaviors.

  18. Plasticizing Effects of Polyamines in Protein-Based Films

    Directory of Open Access Journals (Sweden)

    Mohammed Sabbah

    2017-05-01

    Full Text Available Zeta potential and nanoparticle size were determined on film forming solutions of native and heat-denatured proteins of bitter vetch as a function of pH and of different concentrations of the polyamines spermidine and spermine, both in the absence and presence of the plasticizer glycerol. Our results showed that both polyamines decreased the negative zeta potential of all samples under pH 8.0 as a consequence of their ionic interaction with proteins. At the same time, they enhanced the dimension of nanoparticles under pH 8.0 as a result of macromolecular aggregations. By using native protein solutions, handleable films were obtained only from samples containing either a minimum of 33 mM glycerol or 4 mM spermidine, or both compounds together at lower glycerol concentrations. However, 2 mM spermidine was sufficient to obtain handleable film by using heat-treated samples without glycerol. Conversely, brittle materials were obtained by spermine alone, thus indicating that only spermidine was able to act as an ionic plasticizer. Lastly, both polyamines, mainly spermine, were found able to act as “glycerol-like” plasticizers at concentrations higher than 5 mM under experimental conditions at which their amino groups are undissociated. Our findings open new perspectives in obtaining protein-based films by using aliphatic polycations as components.

  19. Modeling and analysis of film composition on mechanical properties of maize starch based edible films.

    Science.gov (United States)

    Prakash Maran, J; Sivakumar, V; Thirugnanasambandham, K; Kandasamy, S

    2013-11-01

    The present study investigates the influence of composition (content of maize starch (1-3 g), sorbitol (0.5-1.0 ml), agar (0.5-1.0 g) and tween-80 (0.1-0.5 ml)) on the mechanical properties (tensile strength, elongation, Young's modulus, puncture force and puncture deformation) of the maize starch based edible films using four factors with three level Box-Behnken design. The edible films were obtained by casting method. The results showed that, tween-80 increases the permeation of sorbitol in to the polymer matrix. Increasing concentration of sorbitol (hydrophilic nature and plasticizing effect of sorbitol) decreases the tensile strength, Young's modulus and puncture force of the films. The results were analyzed by Pareto analysis of variance (ANOVA) and second order polynomial models were obtained for all responses with high R(2) values (R(2)>0.95). 3D response surface plots were constructed to study the relationship between process variables and the responses. Copyright © 2013 Elsevier B.V. All rights reserved.

  20. Organic Thin-Film Transistor (OTFT-Based Sensors

    Directory of Open Access Journals (Sweden)

    Daniel Elkington

    2014-04-01

    Full Text Available Organic thin film transistors have been a popular research topic in recent decades and have found applications from flexible displays to disposable sensors. In this review, we present an overview of some notable articles reporting sensing applications for organic transistors with a focus on the most recent publications. In particular, we concentrate on three main types of organic transistor-based sensors: biosensors, pressure sensors and “e-nose”/vapour sensors.

  1. Morphology of polymer-based films for organic photovoltaics

    OpenAIRE

    Ruderer, Matthias A.

    2012-01-01

    In this thesis, polymer-based films are examined for applications in organic photovoltaics. Polymer-fullerene, polymer-polymer and diblock copolymer systems are characterized as active layer materials. The focus is on experimental parameters influencing the morphology formation of the active layer in organic solar cells. Scattering and imaging techniques provide a complete understanding of the internal structure on different length scales which is compared to spectroscopic and photovoltaic pr...

  2. Filmless versus film-based systems in radiographic examination costs: an activity-based costing method

    Directory of Open Access Journals (Sweden)

    Sase Yuji

    2011-09-01

    Full Text Available Abstract Background Since the shift from a radiographic film-based system to that of a filmless system, the change in radiographic examination costs and costs structure have been undetermined. The activity-based costing (ABC method measures the cost and performance of activities, resources, and cost objects. The purpose of this study is to identify the cost structure of a radiographic examination comparing a filmless system to that of a film-based system using the ABC method. Methods We calculated the costs of radiographic examinations for both a filmless and a film-based system, and assessed the costs or cost components by simulating radiographic examinations in a health clinic. The cost objects of the radiographic examinations included lumbar (six views, knee (three views, wrist (two views, and other. Indirect costs were allocated to cost objects using the ABC method. Results The costs of a radiographic examination using a filmless system are as follows: lumbar 2,085 yen; knee 1,599 yen; wrist 1,165 yen; and other 1,641 yen. The costs for a film-based system are: lumbar 3,407 yen; knee 2,257 yen; wrist 1,602 yen; and other 2,521 yen. The primary activities were "calling patient," "explanation of scan," "take photographs," and "aftercare" for both filmless and film-based systems. The cost of these activities cost represented 36.0% of the total cost for a filmless system and 23.6% of a film-based system. Conclusions The costs of radiographic examinations using a filmless system and a film-based system were calculated using the ABC method. Our results provide clear evidence that the filmless system is more effective than the film-based system in providing greater value services directly to patients.

  3. Filmless versus film-based systems in radiographic examination costs: an activity-based costing method.

    Science.gov (United States)

    Muto, Hiroshi; Tani, Yuji; Suzuki, Shigemasa; Yokooka, Yuki; Abe, Tamotsu; Sase, Yuji; Terashita, Takayoshi; Ogasawara, Katsuhiko

    2011-09-30

    Since the shift from a radiographic film-based system to that of a filmless system, the change in radiographic examination costs and costs structure have been undetermined. The activity-based costing (ABC) method measures the cost and performance of activities, resources, and cost objects. The purpose of this study is to identify the cost structure of a radiographic examination comparing a filmless system to that of a film-based system using the ABC method. We calculated the costs of radiographic examinations for both a filmless and a film-based system, and assessed the costs or cost components by simulating radiographic examinations in a health clinic. The cost objects of the radiographic examinations included lumbar (six views), knee (three views), wrist (two views), and other. Indirect costs were allocated to cost objects using the ABC method. The costs of a radiographic examination using a filmless system are as follows: lumbar 2,085 yen; knee 1,599 yen; wrist 1,165 yen; and other 1,641 yen. The costs for a film-based system are: lumbar 3,407 yen; knee 2,257 yen; wrist 1,602 yen; and other 2,521 yen. The primary activities were "calling patient," "explanation of scan," "take photographs," and "aftercare" for both filmless and film-based systems. The cost of these activities cost represented 36.0% of the total cost for a filmless system and 23.6% of a film-based system. The costs of radiographic examinations using a filmless system and a film-based system were calculated using the ABC method. Our results provide clear evidence that the filmless system is more effective than the film-based system in providing greater value services directly to patients.

  4. Estimation of structural film viscosity based on the bubble rise method in a nanofluid.

    Science.gov (United States)

    Cho, Heon Ki; Nikolov, Alex D; Wasan, Darsh T

    2018-04-15

    When a single bubble moves at a very low capillary number (10 -7 ) through a liquid with dispersed nanoparticles (nanofluid) inside a vertical tube/capillary, a film is formed between the bubble surface and the tube wall and the nanoparticles self-layer inside the confined film. We measured the film thickness using reflected light interferometry. We calculated the film structural energy isotherm vs. the film thickness from the film-meniscus contact angle measurements using the reflected light interferometric method. Based on the experimental measurement of the film thickness and the calculated values of the film structural energy barrier, we estimated the structural film viscosity vs. the film thickness using the Frenkel approach. Because of the nanoparticle film self-layering phenomenon, we observed a gradual increase in the film viscosity with the decreasing film thickness. However, we observed a significant increase in the film viscosity accompanied by a step-wise decrease in the bubble velocity when the film thickness decreased from 3 to 2 particle layers due to the structural transition in the film. Copyright © 2018 Elsevier Inc. All rights reserved.

  5. Preparation and Properties of Silver Nanowire-Based Transparent Conductive Composite Films

    Science.gov (United States)

    Tian, Ji-Li; Zhang, Hua-Yu; Wang, Hai-Jun

    2016-06-01

    Silver nanowire-based transparent conductive composite films with different structures were successfully prepared using various methods, including liquid polyol, magnetron sputtering and spin coating. The experimental results revealed that the optical transmittance of all different structural composite films decreased slightly (1-3%) compared to pure films. However, the electrical conductivity of all composite films had a great improvement. Under the condition that the optical transmittance was greater than 78% over the wavelength range of 400-800 nm, the AgNW/PVA/AgNW film became a conductor, while the AZO/AgNW/AZO film and the ITO/AgNW/ITO film showed 88.9% and 94% reductions, respectively, for the sheet resistance compared with pure films. In addition, applying a suitable mechanical pressure can improve the conductivity of AgNW-based composite films.

  6. Antimicrobial and physical-mechanical properties of agar-based films incorporated with grapefruit seed extract.

    Science.gov (United States)

    Kanmani, Paulraj; Rhim, Jong-Whan

    2014-02-15

    The use of synthetic petroleum based packaging films caused serious environmental problems due to their difficulty in recycling and poor biodegradability. Therefore, present study was aimed to develop natural biopolymer-based antimicrobial packaging films as an alternative for the synthetic packaging films. As a natural antimicrobial agent, grapefruit seed extract (GSE) has been incorporated into agar to prepare antimicrobial packaging film. The films with different concentrations of GSE were prepared by a solvent casting method and the resulting composite films were examined physically and mechanically. In addition, the films were characterized by FE-SEM, XRD, FT-IR and TGA. The incorporation of GSE caused increase in color, UV barrier, moisture content, water solubility and water vapor permeability, while decrease in surface hydrophobicity, tensile strength and elastic modulus of the films. As the concentration of GSE increased from 0.6 to 13.3 μg/mL, the physical and mechanical properties of the films were affected significantly. The addition of GSE changed film microstructure of the film, but did not influence the crystallinity of agar and thermal stability of the agar-based films. The agar/GSE films exhibited distinctive antimicrobial activity against three test food pathogens, such as Listeria monocytogenes, Bacillus cereus and Escherichia coli. These results suggest that agar/GSE films have potential to be used in an active food packaging systems for maintaining food safety and extending the shelf-life of the packaged food. Copyright © 2013 Elsevier Ltd. All rights reserved.

  7. Identification and annotation of erotic film based on content analysis

    Science.gov (United States)

    Wang, Donghui; Zhu, Miaoliang; Yuan, Xin; Qian, Hui

    2005-02-01

    The paper brings forward a new method for identifying and annotating erotic films based on content analysis. First, the film is decomposed to video and audio stream. Then, the video stream is segmented into shots and key frames are extracted from each shot. We filter the shots that include potential erotic content by finding the nude human body in key frames. A Gaussian model in YCbCr color space for detecting skin region is presented. An external polygon that covered the skin regions is used for the approximation of the human body. Last, we give the degree of the nudity by calculating the ratio of skin area to whole body area with weighted parameters. The result of the experiment shows the effectiveness of our method.

  8. Large displacement vertical translational actuator based on piezoelectric thin films.

    Science.gov (United States)

    Qiu, Zhen; Pulskamp, Jeffrey S; Lin, Xianke; Rhee, Choong-Ho; Wang, Thomas; Polcawich, Ronald G; Oldham, Kenn

    2010-07-01

    A novel vertical translational microactuator based on thin-film piezoelectric actuation is presented, using a set of four compound bend-up/bend-down unimorphs to produce translational motion of a moving platform or stage. The actuation material is a chemical-solution deposited lead-zirconate-titanate (PZT) thin film. Prototype designs have shown as much as 120 μ m of static displacement, with 80-90 μ m displacements being typical, using four 920 μ m long by 70 μ m legs. Analytical models are presented that accurately describe nonlinear behavior in both static and dynamic operation of prototype stages when the dependence of piezoelectric coefficients on voltage is known. Resonance of the system is observed at a frequency of 200 Hz. The large displacement and high bandwidth of the actuators at low-voltage and low-power levels should make them useful to a variety of optical applications, including endoscopic microscopy.

  9. A wrinkling-based method for investigating glassy polymer film relaxation as a function of film thickness and temperature.

    Science.gov (United States)

    Chung, Jun Young; Douglas, Jack F; Stafford, Christopher M

    2017-10-21

    We investigate the relaxation dynamics of thin polymer films at temperatures below the bulk glass transition T g by first compressing polystyrene films supported on a polydimethylsiloxane substrate to create wrinkling patterns and then observing the slow relaxation of the wrinkled films back to their final equilibrium flat state by small angle light scattering. As with recent relaxation measurements on thin glassy films reported by Fakhraai and co-workers, we find the relaxation time of our wrinkled films to be strongly dependent on film thickness below an onset thickness on the order of 100 nm. By varying the temperature between room temperature and T g (≈100 °C), we find that the relaxation time follows an Arrhenius-type temperature dependence to a good approximation at all film thicknesses investigated, where both the activation energy and the relaxation time pre-factor depend appreciably on film thickness. The wrinkling relaxation curves tend to cross at a common temperature somewhat below T g , indicating an entropy-enthalpy compensation relation between the activation free energy parameters. This compensation effect has also been observed recently in simulated supported polymer films in the high temperature Arrhenius relaxation regime rather than the glassy state. In addition, we find that the film stress relaxation function, as well as the height of the wrinkle ridges, follows a stretched exponential time dependence and the short-time effective Young's modulus derived from our modeling decreases sigmoidally with increasing temperature-both characteristic features of glassy materials. The relatively facile nature of the wrinkling-based measurements in comparison to other film relaxation measurements makes our method attractive for practical materials development, as well as fundamental studies of glass formation.

  10. Study of carbon nanotubes based Polydimethylsiloxane composite films

    International Nuclear Information System (INIS)

    Shahzad, M I; Giorcelli, M; Shahzad, N; Guastella, S; Castellino, M; Jagdale, P; Tagliaferro, A

    2013-01-01

    Thanks to their remarkable characteristics, carbon nanotubes (CNTs) have fields of applications which are growing every day. Among them, the use of CNTs as filler for polymers is one of the most promising. In this work we report on Polydimethylsiloxane (PDMS) composites with different weight percentages (0.0% to 3.0%) of multiwall carbon nanotubes (MWCNTs) having diameter 10–30 nm and length 20–30 μm. To achieve optimum dispersion of CNTs in PDMS matrix, high speed mechanical stirring and ultrasonication were performed. By using the doctor blade technique, 70 μm thick uniform films were produced on glass. They were subsequently thermally cured and detached from the glass to get flexible and self standing films. The surface morphological study done by FESEM, shows that CNTs are well dispersed in the PDMS. Raman spectroscopy and FTIR were used to investigate the possible structural changes in the polymer composite. To examine the optical behavior UV-VIS spectroscopy was employed in both specular and diffused modes. A linear increase in absorption coefficient is found with the increasing percentage of CNTs while the transmittance decreases exponentially. The results confirm the dependence of optical limiting effect on the quantity of MWCNTs. Based on optical study, MWCNTs/PDMS composite films can be a promising material to extend performances of optical limiters against laser pulses, which is often required in lasing systems.

  11. Electrochromic Devices Based on Porous Tungsten Oxide Thin Films

    Directory of Open Access Journals (Sweden)

    Y. Djaoued

    2012-01-01

    Full Text Available Recent developments in the synthesis of transition metal oxides in the form of porous thin films have opened up opportunities in the construction of electrochromic devices with enhanced properties. In this paper, synthesis, characterization and electrochromic applications of porous WO3 thin films with different nanocrystalline phases, such as hexagonal, monoclinic, and orthorhombic, are presented. Asymmetric electrochromic devices have been constructed based on these porous WO3 thin films. XRD measurements of the intercalation/deintercalation of Li+ into/from the WO3 layer of the device as a function of applied coloration/bleaching voltages show systematic changes in the lattice parameters associated with structural phase transitions in LixWO3. Micro-Raman studies show systematic crystalline phase changes in the spectra of WO3 layers during Li+ ion intercalation and deintercalation, which agree with the XRD data. These devices exhibit interesting optical modulation (up to ~70% due to intercalation/deintercalation of Li ions into/from the WO3 layer of the devices as a function of applied coloration/bleaching voltages. The obtained optical modulation of the electrochromic devices indicates that, they are suitable for applications in electrochromic smart windows.

  12. Preparation and properties of carbohydrate-based composite films incorporated with CuO nanoparticles.

    Science.gov (United States)

    Shankar, Shiv; Wang, Long-Feng; Rhim, Jong-Whan

    2017-08-01

    The present study aimed to develop the carbohydrate biopolymer based antimicrobial films for food packaging application. The nanocomposite films of various biopolymers and copper oxide nanoparticles (CuONPs) were prepared by solvent casting method. The nanocomposite films were characterized using SEM, FTIR, XRD, and UV-vis spectroscopy. The thermal stability, UV barrier, water vapor permeability, and antibacterial activity of the composite films were also evaluated. The surface morphology of the films was dependent on the types of polymers used. The XRD revealed the crystallinity of CuONPs in the composite films. The addition of CuONPs increased the thickness, tensile strength, UV barrier property, relative humidity, and water vapor barrier property. The CuONPs incorporated composite films exhibited strong antibacterial activity against Escherichia coli and Listeria monocytogenes. The developed composite films could be used as a UV-light barrier antibacterial films for active food packaging. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. Characterization of Kerfless Linear Arrays Based on PZT Thick Film.

    Science.gov (United States)

    Zawada, Tomasz; Bierregaard, Louise Moller; Ringgaard, Erling; Xu, Ruichao; Guizzetti, Michele; Levassort, Franck; Certon, Dominique

    2017-09-01

    Multielement transducers enabling novel cost-effective fabrication of imaging arrays for medical applications have been presented earlier. Due to the favorable low lateral coupling of the screen-printed PZT, the elements can be defined by the top electrode pattern only, leading to a kerfless design with low crosstalk between the elements. The thick-film-based linear arrays have proved to be compatible with a commercial ultrasonic scanner and to support linear array beamforming as well as phased array beamforming. The main objective of the presented work is to investigate the performance of the devices at the transducer level by extensive measurements of the test structures. The arrays have been characterized by several different measurement techniques. First, electrical impedance measurements on several elements in air and liquid have been conducted in order to support material parameter identification using the Krimholtz-Leedom-Matthaei model. It has been found that electromechanical coupling is at the level of 35%. The arrays have also been characterized by a pulse-echo system. The measured sensitivity is around -60 dB, and the fractional bandwidth is close to 60%, while the center frequency is about 12 MHz over the whole array. Finally, laser interferometry measurements have been conducted indicating very good displacement level as well as pressure. The in-depth characterization of the array structure has given insight into the performance parameters for the array based on PZT thick film, and the obtained information will be used to optimize the key parameters for the next generation of cost-effective arrays based on piezoelectric thick film.

  14. Gallic acid as an oxygen scavenger in bio-based multilayer packaging films

    OpenAIRE

    Pant, Astrid; Sängerlaub, Sven; Müller, Kajetan

    2017-01-01

    Oxygen scavengers are used in food packaging to protect oxygen-sensitive food products. A mixture of gallic acid (GA) and sodium carbonate was used as an oxygen scavenger (OSc) in bio-based multilayer packaging films produced in a three-step process: compounding, flat film extrusion, and lamination. We investigated the film surface color as well as oxygen absorption at different relative humidities (RHs) and temperatures, and compared the oxygen absorption of OSc powder, monolayer films, and ...

  15. Functional chitosan-based grapefruit seed extract composite films for applications in food packaging technology

    International Nuclear Information System (INIS)

    Tan, Y.M.; Lim, S.H.; Tay, B.Y.; Lee, M.W.; Thian, E.S.

    2015-01-01

    Highlights: • Chitosan-based grapefruit seed extract (GFSE) films were solution casted. • GFSE was uniformly dispersed within all chitosan film matrices. • All chitosan-based composite films showed remarkable transparency. • Increasing amounts of GFSE incorporated increased the elongation at break of films. • Chitosan-based GFSE composite films inhibited the proliferation of fungal growth. - Abstract: Chitosan-based composite films with different amounts of grapefruit seed extract (GFSE) (0.5, 1.0 and 1.5% v/v) were fabricated via solution casting technique. Experimental results showed that GFSE was uniformly dispersed within all chitosan film matrices. The presence of GFSE made the films more amorphous and tensile strength decreased, while elongation at break values increased as GFSE content increased. Results from the measurement of light transmission revealed that increasing amounts of GFSE (from 0.5 to 1.5% v/v) did not affect transparency of the films. Furthermore, packaging of bread samples with chitosan-based GFSE composite films inhibited the proliferation of fungal growth as compared to control samples. Hence, chitosan-based GFSE composite films have the potential to be a useful material in the area of food technology

  16. Functional chitosan-based grapefruit seed extract composite films for applications in food packaging technology

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Y.M. [Department of Mechanical Engineering, National University of Singapore (Singapore); Lim, S.H.; Tay, B.Y. [Forming Technology Group, Singapore Institute of Manufacturing Technology (Singapore); Lee, M.W. [Food Innovation and Resource Centre, Singapore Polytechnic (Singapore); Thian, E.S., E-mail: mpetes@nus.edu.sg [Department of Mechanical Engineering, National University of Singapore (Singapore)

    2015-09-15

    Highlights: • Chitosan-based grapefruit seed extract (GFSE) films were solution casted. • GFSE was uniformly dispersed within all chitosan film matrices. • All chitosan-based composite films showed remarkable transparency. • Increasing amounts of GFSE incorporated increased the elongation at break of films. • Chitosan-based GFSE composite films inhibited the proliferation of fungal growth. - Abstract: Chitosan-based composite films with different amounts of grapefruit seed extract (GFSE) (0.5, 1.0 and 1.5% v/v) were fabricated via solution casting technique. Experimental results showed that GFSE was uniformly dispersed within all chitosan film matrices. The presence of GFSE made the films more amorphous and tensile strength decreased, while elongation at break values increased as GFSE content increased. Results from the measurement of light transmission revealed that increasing amounts of GFSE (from 0.5 to 1.5% v/v) did not affect transparency of the films. Furthermore, packaging of bread samples with chitosan-based GFSE composite films inhibited the proliferation of fungal growth as compared to control samples. Hence, chitosan-based GFSE composite films have the potential to be a useful material in the area of food technology.

  17. PET based nanocomposite films for microwave packaging applications

    International Nuclear Information System (INIS)

    Galdi, M. R.; Olivieri, R.; Liguori, L.; Albanese, D.; Di Matteo, M.; Di Maio, L.

    2015-01-01

    In recent years, changes in life standards have promoted the diffusion of Ready to Cook (RTC) and Ready to Eat (RTE) products for microwave ovens. However, the main limits in microwave (MW) ovens usage are often related to the proper choice of packaging materials suitable for such technology. In fact, packages for microwaveable RTC and RTE foods should ensure adequate preservation of the product before cooking/heating such as high barriers to gases and aromas and adequate control of water vapor transmission. In addition, microwaveable packaging material must be transparent to MW, thermally stable and resistant to the mechanical stress induced by the accumulation in the head space of volatile substances produced during the cooking. Polymeric materials are good candidates for microwaveable packaging thanks to their transparency to MW. In the last years a great interest is devoted to developing innovative solution based on the use of additives or systems that act as susceptors or heating enhancers for improving the characteristics of polymers in cooking/heating in MW ovens. The present work was focused on the production and characterization of nanocomposite copolyester based films suitable for microwaveable food packaging applications. The matrices selected consist in two PET copolymers modified with carbon black (ULTRA STD) and with titanium oxide (ULTRA NA). Nanocomposite co-extruded multilayer films were produced using different percentages (0%, 2% and 4%wt/wt) of Cloisite 20A (C20A). Films were analyzed for evaluating the effect of nanofiller on the morphology and barrier properties. Moreover, to verify the effectiveness of the designed systems in reducing the cooking times of meat products, MW heating tests were carried out on pork meat hamburgers in MW oven at varying supplied powers. The cooking tests have pointed out that the selected matrices are efficient in reducing cooking times and that even low concentration of C20A acts as heating enhancers of PET

  18. PET based nanocomposite films for microwave packaging applications

    Energy Technology Data Exchange (ETDEWEB)

    Galdi, M. R., E-mail: mrgaldi@unisa.it; Olivieri, R.; Liguori, L.; Albanese, D., E-mail: dalbanese@unisa.it; Di Matteo, M.; Di Maio, L., E-mail: ldimaio@unisa.it [Industrial Engineering Department, University of Salerno, Via Giovanni Paolo II 132, 84084 Fisciano (Italy)

    2015-12-17

    In recent years, changes in life standards have promoted the diffusion of Ready to Cook (RTC) and Ready to Eat (RTE) products for microwave ovens. However, the main limits in microwave (MW) ovens usage are often related to the proper choice of packaging materials suitable for such technology. In fact, packages for microwaveable RTC and RTE foods should ensure adequate preservation of the product before cooking/heating such as high barriers to gases and aromas and adequate control of water vapor transmission. In addition, microwaveable packaging material must be transparent to MW, thermally stable and resistant to the mechanical stress induced by the accumulation in the head space of volatile substances produced during the cooking. Polymeric materials are good candidates for microwaveable packaging thanks to their transparency to MW. In the last years a great interest is devoted to developing innovative solution based on the use of additives or systems that act as susceptors or heating enhancers for improving the characteristics of polymers in cooking/heating in MW ovens. The present work was focused on the production and characterization of nanocomposite copolyester based films suitable for microwaveable food packaging applications. The matrices selected consist in two PET copolymers modified with carbon black (ULTRA STD) and with titanium oxide (ULTRA NA). Nanocomposite co-extruded multilayer films were produced using different percentages (0%, 2% and 4%wt/wt) of Cloisite 20A (C20A). Films were analyzed for evaluating the effect of nanofiller on the morphology and barrier properties. Moreover, to verify the effectiveness of the designed systems in reducing the cooking times of meat products, MW heating tests were carried out on pork meat hamburgers in MW oven at varying supplied powers. The cooking tests have pointed out that the selected matrices are efficient in reducing cooking times and that even low concentration of C20A acts as heating enhancers of PET.

  19. PET based nanocomposite films for microwave packaging applications

    Science.gov (United States)

    Galdi, M. R.; Olivieri, R.; Liguori, L.; Albanese, D.; Di Matteo, M.; Di Maio, L.

    2015-12-01

    In recent years, changes in life standards have promoted the diffusion of Ready to Cook (RTC) and Ready to Eat (RTE) products for microwave ovens. However, the main limits in microwave (MW) ovens usage are often related to the proper choice of packaging materials suitable for such technology. In fact, packages for microwaveable RTC and RTE foods should ensure adequate preservation of the product before cooking/heating such as high barriers to gases and aromas and adequate control of water vapor transmission. In addition, microwaveable packaging material must be transparent to MW, thermally stable and resistant to the mechanical stress induced by the accumulation in the head space of volatile substances produced during the cooking. Polymeric materials are good candidates for microwaveable packaging thanks to their transparency to MW. In the last years a great interest is devoted to developing innovative solution based on the use of additives or systems that act as susceptors or heating enhancers for improving the characteristics of polymers in cooking/heating in MW ovens. The present work was focused on the production and characterization of nanocomposite copolyester based films suitable for microwaveable food packaging applications. The matrices selected consist in two PET copolymers modified with carbon black (ULTRA STD) and with titanium oxide (ULTRA NA). Nanocomposite co-extruded multilayer films were produced using different percentages (0%, 2% and 4%wt/wt) of Cloisite 20A (C20A). Films were analyzed for evaluating the effect of nanofiller on the morphology and barrier properties. Moreover, to verify the effectiveness of the designed systems in reducing the cooking times of meat products, MW heating tests were carried out on pork meat hamburgers in MW oven at varying supplied powers. The cooking tests have pointed out that the selected matrices are efficient in reducing cooking times and that even low concentration of C20A acts as heating enhancers of PET.

  20. Release behavior and stability of encapsulated D-limonene from emulsion-based edible films.

    Science.gov (United States)

    Marcuzzo, Eva; Debeaufort, Frédéric; Sensidoni, Alessandro; Tat, Lara; Beney, Laurent; Hambleton, Alicia; Peressini, Donatella; Voilley, Andrée

    2012-12-12

    Edible films may act as carriers of active molecules, such as flavors. This possibility confers to them the status of active packaging. Two different film-forming biopolymers, gluten and ι-carrageenans, have been compared. D-Limonene was added to the two film formulations, and its release kinetics from emulsion-based edible films was assessed with HS-SPME. Results obtained for edible films were compared with D-limonene released from the fatty matrix called Grindsted Barrier System 2000 (GBS). Comparing ι-carrageenans with gluten-emulsified film, the latter showed more interesting encapsulating properties: in fact, D-limonene was retained by gluten film during the process needed for film preparation, and it was released gradually during analysis time. D-Limonene did not show great affinity to ι-carrageenans film, maybe due to high aroma compound hydrophobicity. Carvone release from the three different matrices was also measured to verify the effect of oxygen barrier performances of edible films to prevent D-limonene oxidation. Further investigations were carried out by FT-IR and liquid permeability measurements. Gluten film seemed to better protect D-limonene from oxidation. Gluten-based edible films represent an interesting opportunity as active packaging: they could retain and release aroma compounds gradually, showing different mechanical and nutritional properties from those of lipid-based ingredients.

  1. Graphene-based flexible and stretchable thin film transistors.

    Science.gov (United States)

    Yan, Chao; Cho, Jeong Ho; Ahn, Jong-Hyun

    2012-08-21

    Graphene has been attracting wide attention owing to its superb electronic, thermal and mechanical properties. These properties allow great applications in the next generation of optoelectronics, where flexibility and stretchability are essential. In this context, the recent development of graphene growth/transfer and its applications in field-effect transistors are involved. In particular, we provide a detailed review on the state-of-the-art of graphene-based flexible and stretchable thin film transistors. We address the principles of fabricating high-speed graphene analog transistors and the key issues of producing an array of graphene-based transistors on flexible and stretchable substrates. It provides a platform for future work to focus on understanding and realizing high-performance graphene-based transistors.

  2. Paper-based transparent flexible thin film supercapacitors

    Science.gov (United States)

    Gao, Kezheng; Shao, Ziqiang; Wu, Xue; Wang, Xi; Zhang, Yunhua; Wang, Wenjun; Wang, Feijun

    2013-05-01

    Paper-based transparent flexible thin film supercapacitors were fabricated using CNF-[RGO]n hybrid paper as an electrode material and charge collector. Owing to the self-anti-stacking of distorted RGO nanosheets and internal electrolyte nanoscale-reservoirs, the device exhibited good electrochemical performance (about 1.73 mF cm-2), and a transmittance of about 56% (at 550 nm).Paper-based transparent flexible thin film supercapacitors were fabricated using CNF-[RGO]n hybrid paper as an electrode material and charge collector. Owing to the self-anti-stacking of distorted RGO nanosheets and internal electrolyte nanoscale-reservoirs, the device exhibited good electrochemical performance (about 1.73 mF cm-2), and a transmittance of about 56% (at 550 nm). Electronic supplementary information (ESI) available: Experimental, TEM image, IR spectra, and XRD spectra of cellulose nanofibers, TEM image, and XRD spectra of RGO, graphite, GO nanosheets, CNF paper, and CNF-[RGO]20 hybrid paper, high-resolution C1s spectra of GO, Raman spectra of GO nanosheets, cross-sectional FESEM image of CNF-[RGO]20 hybrid paper and stress-strain curve of T-SC-20. See DOI: 10.1039/c3nr00674c

  3. PVDF-PZT nanocomposite film based self-charging power cell.

    Science.gov (United States)

    Zhang, Yan; Zhang, Yujing; Xue, Xinyu; Cui, Chunxiao; He, Bin; Nie, Yuxin; Deng, Ping; Lin Wang, Zhong

    2014-03-14

    A novel PVDF-PZT nanocomposite film has been proposed and used as a piezoseparator in self-charging power cells (SCPCs). The structure, composed of poly(vinylidene fluoride) (PVDF) and lead zirconate titanate (PZT), provides a high piezoelectric output, because PZT in this nanocomposite film can improve the piezopotential compared to the pure PVDF film. The SCPC based on this nanocomposite film can be efficiently charged up by the mechanical deformation in the absence of an external power source. The charge capacity of the PVDF-PZT nanocomposite film based SCPC in 240 s is ∼0.010 μA h, higher than that of a pure PVDF film based SCPC (∼0.004 μA h). This is the first demonstration of using PVDF-PZT nanocomposite film as a piezoseparator for SCPC, and is an important step for the practical applications of SCPC for harvesting and storing mechanical energy.

  4. Nucleophilic stabilization of water-based reactive ink for titania-based thin film inkjet printing

    DEFF Research Database (Denmark)

    Gadea, Christophe; Marani, Debora; Esposito, Vincenzo

    2017-01-01

    Drop on demand deposition (DoD) of titanium oxide thin films (<500 nm) is performed via a novel titanium-alkoxide-based solution that is tailored as a reactive ink for inkjet printing. The ink is developed as water-based solution by a combined use of titanium isopropoxide and n-methyldiethanolami...

  5. Towards a Script-Based Representation Language for Educational Films.

    Science.gov (United States)

    Parkes, Alan P.

    1987-01-01

    Discusses aspects of the syntax and semantics of film, and presents a scenario for the use of film by intelligent computer assisted instruction (ICAI) systems. An outline of a representation language for educational films on videodisc is presented, and an appendix provides conceptual graphs that explain notations used in examples. (Author/LRW)

  6. Thin-film filament-based solar cells and modules

    Science.gov (United States)

    Tuttle, J. R.; Cole, E. D.; Berens, T. A.; Alleman, J.; Keane, J.

    1997-04-01

    This concept paper describes a patented, novel photovoltaic (PV) technology that is capable of achieving near-term commercialization and profitability based upon design features that maximize product performance while minimizing initial and future manufacturing costs. DayStar Technologies plans to exploit these features and introduce a product to the market based upon these differential positions. The technology combines the demonstrated performance and reliability of existing thin-film PV product with a cell and module geometry that cuts material usage by a factor of 5, and enhances performance and manufacturability relative to standard flat-plate designs. The target product introduction price is 1.50/Watt-peak (Wp). This is approximately one-half the cost of the presently available PV product. Additional features include: increased efficiency through low-level concentration, no scribe or grid loss, simple series interconnect, high voltage, light weight, high-throughput manufacturing, large area immediate demonstration, flexibility, modularity.

  7. Epitaxial growth of Fe-based superconductor thin films

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, Sven; Haenisch, Jens; Holzapfel, Bernhard [Institut fuer Technische Physik, Karlsruher Institut fuer Technologie, Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen (Germany)

    2016-07-01

    The Fe-based superconductors (FBS), discovered in 2008, are not only interesting for possible applications due to their large upper critical fields and low anisotropies, but also for basic understanding of unconventional superconductivity. With their properties, they constitute a link between the classic low-T{sub c} superconductors (low anisotropies, low thermal fluctuations, s-wave type symmetry) and the oxocuprates (T{sub c} up to 55 K, large H{sub c2}, unconventional pairing). Their multi-band nature reminds of MgB{sub 2}. We prepare thin films of FBS in the so called 122 family, namely Co- and P-doped BaFe{sub 2}As{sub 2} to investigate application relevant properties, such as critical current density J{sub c}, by pulsed laser deposition using a frequency-tripled Nd:YAG laser (λ = 355 nm). Microstructure and chemical composition will be investigated by XRD, AFM and SEM, and electrical transport using a 14 T PPMS. The results are compared to literature data on films grown at different wavelengths.

  8. Monolithic acoustic graphene transistors based on lithium niobate thin film

    Science.gov (United States)

    Liang, J.; Liu, B.-H.; Zhang, H.-X.; Zhang, H.; Zhang, M.-L.; Zhang, D.-H.; Pang, W.

    2018-05-01

    This paper introduces an on-chip acoustic graphene transistor based on lithium niobate thin film. The graphene transistor is embedded in a microelectromechanical systems (MEMS) acoustic wave device, and surface acoustic waves generated by the resonator induce a macroscopic current in the graphene due to the acousto-electric (AE) effect. The acoustic resonator and the graphene share the lithium niobate film, and a gate voltage is applied through the back side of the silicon substrate. The AE current induced by the Rayleigh and Sezawa modes was investigated, and the transistor outputs a larger current in the Rayleigh mode because of a larger coupling to velocity ratio. The output current increases linearly with the input radiofrequency power and can be effectively modulated by the gate voltage. The acoustic graphene transistor realized a five-fold enhancement in the output current at an optimum gate voltage, outperforming its counterpart with a DC input. The acoustic graphene transistor demonstrates a paradigm for more-than-Moore technology. By combining the benefits of MEMS and graphene circuits, it opens an avenue for various system-on-chip applications.

  9. Crack width monitoring of concrete structures based on smart film

    International Nuclear Information System (INIS)

    Zhang, Benniu; Wang, Shuliang; Li, Xingxing; Zhang, Xu; Yang, Guang; Qiu, Minfeng

    2014-01-01

    Due to its direct link to structural security, crack width is thought to be one of the most important parameters reflecting damage conditions of concrete structures. However, the width problem is difficult to solve with the existing structural health monitoring methods. In this paper, crack width monitoring by means of adhering enameled copper wires with different ultimate strains on the surface of structures is proposed, based on smart film crack monitoring put forward by the present authors. The basic idea of the proposed method is related to a proportional relationship between the crack width and ultimate strain of the broken wire. Namely, when a certain width of crack passes through the wire, some low ultimate strain wires will be broken and higher ultimate strain wires may stay non-broken until the crack extends to a larger scale. Detection of the copper wire condition as broken or non-broken may indicate the width of the structural crack. Thereafter, a multi-layered stress transfer model and specimen experiment are performed to quantify the relationship. A practical smart film is then redesigned with this idea and applied to Chongqing Jiangjin Yangtze River Bridge. (paper)

  10. Crack width monitoring of concrete structures based on smart film

    Science.gov (United States)

    Zhang, Benniu; Wang, Shuliang; Li, Xingxing; Zhang, Xu; Yang, Guang; Qiu, Minfeng

    2014-04-01

    Due to its direct link to structural security, crack width is thought to be one of the most important parameters reflecting damage conditions of concrete structures. However, the width problem is difficult to solve with the existing structural health monitoring methods. In this paper, crack width monitoring by means of adhering enameled copper wires with different ultimate strains on the surface of structures is proposed, based on smart film crack monitoring put forward by the present authors. The basic idea of the proposed method is related to a proportional relationship between the crack width and ultimate strain of the broken wire. Namely, when a certain width of crack passes through the wire, some low ultimate strain wires will be broken and higher ultimate strain wires may stay non-broken until the crack extends to a larger scale. Detection of the copper wire condition as broken or non-broken may indicate the width of the structural crack. Thereafter, a multi-layered stress transfer model and specimen experiment are performed to quantify the relationship. A practical smart film is then redesigned with this idea and applied to Chongqing Jiangjin Yangtze River Bridge.

  11. Experimental Comparison of the Behavior between Base Oil and Grease Starvation Based on Inlet Film Thickness

    Directory of Open Access Journals (Sweden)

    D. Kostal

    2017-03-01

    Full Text Available This paper deals with the experimental study of an elastohydrodynamic contact under conditions of insufficient lubricant supply. Starvation level of this type of the contact may be experimentally determined based on the position of the meniscus, but this way can't determine all levels of starvation. Consequent development in the field of tribology achieved theoretical model that can determine all levels of starvation by dependency on the thickness of the lubricant film entering the contact, but it is difficult for experimental verification. The main goal of this work is an experimental study and description of the behavior of the elastohydrodynamic contact with controlled thickness of the lubricant film at the contact input. Contact was lubricated by the base oil and the grease and compared. Results were surprising because the only differences between oil and grease were observed for more viscous lubricants at thicker film layer entering to the contact.

  12. A sensor of alcohol vapours based on thin polyaniline base film and quartz crystal microbalance.

    Science.gov (United States)

    Ayad, Mohamad M; El-Hefnawey, Gad; Torad, Nagy L

    2009-08-30

    Thin films of polyaniline base, emeraldine base (EB), coating on the quartz crystal microbalance (QCM) electrode were used as a sensitive layer for the detection of a number of primary aliphatic alcohols such as ethanol, methanol, 2-propanol and 1-propanol vapours. The frequency shifts (Deltaf) of the QCM were increased due to the vapour adsorption into the EB film. Deltaf were found to be linearly correlated with the concentrations of alcohols vapour in part per million (ppm). The sensitivity of the sensor was found to be governed by the chemical structure of the alcohol. The sensor shows a good reproducibility and reversibility. The diffusions of different alcohols vapour were studied and the diffusion coefficients (D) were calculated. It is concluded that the diffusion of the vapours into the EB film follows Fickian kinetics.

  13. Electrodeposited Fe-Co films prepared from a citric-acid-based plating bath

    OpenAIRE

    Yanai, Takeshi; Uto, H.; Shimokawa, Takaya; Nakano, Masaki; Fukunaga, Hirotoshi; Suzuki, K.

    2013-01-01

    Electrodeposited Fe-Co films are commonly prepared in a boric-acid-based bath. In this research, we applied citric acid instead of boric acid for the plating of Fe-Co films because boron in the waste bath is restricted by environmental-protection regulations in Japan. We evaluated the effect of citric acid on the magnetic and structural properties of the films. The saturation magnetization of the Fe-Co films slightly increased while the Fe content in the Fe-Co films decreased with increasing ...

  14. Development of 3D Slicer based film dosimetry analysis

    International Nuclear Information System (INIS)

    Alexander, K M; Schreiner, L J; Robinson, A; Pinter, C; Fichtinger, G

    2017-01-01

    Radiochromic film dosimetry has been widely adopted in the clinic as it is a convenient option for dose measurement and verification. Film dosimetry analysis is typically performed using expensive commercial software, or custom made scripts in Matlab. However, common clinical film analysis software is not transparent regarding what corrections/optimizations are running behind the scenes. In this work, an extension to the open-source medical imaging platform 3D Slicer was developed and implemented in our centre for film dosimetry analysis. This extension streamlines importing treatment planning system dose and film imaging data, film calibration, registration, and comparison of 2D dose distributions, enabling greater accessibility to film analysis and higher reliability. (paper)

  15. Tungsten oxide proton conducting films for low-voltage transparent oxide-based thin-film transistors

    International Nuclear Information System (INIS)

    Zhang, Hongliang; Wan, Qing; Wan, Changjin; Wu, Guodong; Zhu, Liqiang

    2013-01-01

    Tungsten oxide (WO x ) electrolyte films deposited by reactive magnetron sputtering showed a high room temperature proton conductivity of 1.38 × 10 −4 S/cm with a relative humidity of 60%. Low-voltage transparent W-doped indium-zinc-oxide thin-film transistors gated by WO x -based electrolytes were self-assembled on glass substrates by one mask diffraction method. Enhancement mode operation with a large current on/off ratio of 4.7 × 10 6 , a low subthreshold swing of 108 mV/decade, and a high field-effect mobility 42.6 cm 2 /V s was realized. Our results demonstrated that WO x -based proton conducting films were promising gate dielectric candidates for portable low-voltage oxide-based devices.

  16. Graphene-based supercapacitor with carbon nanotube film as highly efficient current collector

    International Nuclear Information System (INIS)

    Notarianni, Marco; Liu, Jinzhang; Motta, Nunzio; Mirri, Francesca; Pasquali, Matteo

    2014-01-01

    Flexible graphene-based thin film supercapacitors were made using carbon nanotube (CNT) films as current collectors and graphene films as electrodes. The graphene sheets were produced by simple electrochemical exfoliation, while the graphene films with controlled thickness were prepared by vacuum filtration. The solid-state supercapacitor was made by using two graphene/CNT films on plastic substrates to sandwich a thin layer of gelled electrolyte. We found that the thin graphene film with thickness <1 μm can greatly increase the capacitance. Using only CNT films as electrodes, the device exhibited a capacitance as low as ∼0.4 mF cm −2 , whereas by adding a 360 nm thick graphene film to the CNT electrodes led to a ∼4.3 mF cm −2 capacitance. We experimentally demonstrated that the conductive CNT film is equivalent to gold as a current collector while it provides a stronger binding force to the graphene film. Combining the high capacitance of the thin graphene film and the high conductivity of the CNT film, our devices exhibited high energy density (8–14 Wh kg −1 ) and power density (250–450 kW kg −1 ). (paper)

  17. Printed organic thin-film transistor-based integrated circuits

    International Nuclear Information System (INIS)

    Mandal, Saumen; Noh, Yong-Young

    2015-01-01

    Organic electronics is moving ahead on its journey towards reality. However, this technology will only be possible when it is able to meet specific criteria including flexibility, transparency, disposability and low cost. Printing is one of the conventional techniques to deposit thin films from solution-based ink. It is used worldwide for visual modes of information, and it is now poised to enter into the manufacturing processes of various consumer electronics. The continuous progress made in the field of functional organic semiconductors has achieved high solubility in common solvents as well as high charge carrier mobility, which offers ample opportunity for organic-based printed integrated circuits. In this paper, we present a comprehensive review of all-printed organic thin-film transistor-based integrated circuits, mainly ring oscillators. First, the necessity of all-printed organic integrated circuits is discussed; we consider how the gap between printed electronics and real applications can be bridged. Next, various materials for printed organic integrated circuits are discussed. The features of these circuits and their suitability for electronics using different printing and coating techniques follow. Interconnection technology is equally important to make this product industrially viable; much attention in this review is placed here. For high-frequency operation, channel length should be sufficiently small; this could be achievable with a combination of surface treatment-assisted printing or laser writing. Registration is also an important issue related to printing; the printed gate should be perfectly aligned with the source and drain to minimize parasitic capacitances. All-printed organic inverters and ring oscillators are discussed here, along with their importance. Finally, future applications of all-printed organic integrated circuits are highlighted. (paper)

  18. Keratin based bioplastic film from chicken feathers and its characterization.

    Science.gov (United States)

    Ramakrishnan, Navina; Sharma, Swati; Gupta, Arun; Alashwal, Basma Yahya

    2018-05-01

    Plastics have been one of the highly valued materials and it plays an significant role in human's life such as in food packaging and biomedical applications. Bioplastic materials can gradually work as a substitute for various materials based on fossil oil. The issue like sustainability and environmental challenges which occur due to manufacturing and disposal of synthetic plastics can be conquering by bio-based plastics. Feathers are among the most inexpensive abundant, and renewable protein sources. Feathers disposal to the landfills leads to environmental pollutions and it results into wastage of 90% of protein raw material. Keratin is non-burning hydrophilic, and biodegradable due to which it can be applicable in various ways via chemical processing. Main objective of this research is to synthesis bioplastic using keratin from chicken feathers. Extracted keratin solution mixed with different concentration of glycerol (2 to 10%) to produce plastic films. The mixture was stirred under constant magnetic stirring at 60 °C for 5 h. The mixtures are then poured into aluminum weighing boat and dried in an oven at 60 °C for 24 h. The mechanical properties of the samples were tested and the physic-chemical properties of the bioplastic were studied. According to the results, Scanning Electron Microscopy test showed good compatible morphologies without holes, cavity and edge. The difference in chemical composition was analyzed using Fourier transform infrared spectroscopy (FTIR). The samples were also characterized by thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC), X-Ray diffraction (XRD) to check the thermal and crystallinity properties. Other than that, bioplastic made up from keratin with 2% of glycerol has the best mechanical and thermal properties. According to biodegradability test, all bioplastic produced are proven biodegradable. Therefore, the results showed possible application of the film as an alternative to fossil oil

  19. Gelatin-Based Films and Coatings for Food Packaging Applications

    Directory of Open Access Journals (Sweden)

    Marina Ramos

    2016-09-01

    Full Text Available This review discusses the latest advances in the composition of gelatin-based edible films and coatings, including nanoparticle addition, and their properties are reviewed along their potential for application in the food packaging industry. Gelatin is an important biopolymer derived from collagen and is extensively used by various industries because of its technological and functional properties. Nowadays, a very wide range of components are available to be included as additives to improve its properties, as well as its applications and future potential. Antimicrobials, antioxidants and other agents are detailed due to the fact that an increasing awareness among consumers regarding healthy lifestyle has promoted research into novel techniques and additives to prolong the shelf life of food products. Thanks to its ability to improve global food quality, gelatin has been particularly considered in food preservation of meat and fish products, among others.

  20. SUBTLEX- AL: Albanian word frequencies based on film subtitles

    Directory of Open Access Journals (Sweden)

    Dr.Sc. Rrezarta Avdyli

    2013-06-01

    Full Text Available Recently several studies have shown that word frequency estimation based on subtitle files explains better the variance in word recognition performance than traditional words frequency estimates did. The present study aims to show this frequency estimate in Albanian from more than 2M words coming from film subtitles. Our results show high correlation between the RT from a LD study (120 stimuli and the SUBTLEX- AL, as well as, high correlation between this and the unique existing frequency list of a hundred more frequent Albanian words. These findings suggest that SUBTLEX-AL it is good frequency estimation, furthermore, this is the first database of frequency estimation in Albanian larger than 100 words.

  1. Development and characterization of novel antimicrobial bilayer films based on Polylactic acid (PLA)/Pickering emulsions.

    Science.gov (United States)

    Zhu, Jun-You; Tang, Chuan-He; Yin, Shou-Wei; Yang, Xiao-Quan

    2018-02-01

    Biodegradable food packaging is sustainable and has a great application prospect. PLA is a promising alternative for petroleum-derived polymers. However, PLA packaging suffers from poor barrier properties compared with petroleum-derived ones. To address this issue, we designed bilayer films based on PLA and Pickering emulsions. The formed bilayer films were compact and uniform and double layers were combined firmly. This strategy enhanced mechanical resistance, ductility and moisture barrier of Pickering emulsion films, and concomitantly enhanced the oxygen barrier for PLA films. Thymol loadings in Pickering emulsion layer endowed them with antimicrobial and antioxidant activity. The release profile of thymol was well fitted with Fick's second law. The antimicrobial activity of the films depended on film types, and Pickering emulsion layer presented larger inhibition zone than PLA layer, hinting that the films possessed directional releasing role. This study opens a promising route to fabricate bilayer architecture creating synergism of each layer. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Films based on oxidized starch and cellulose from barley.

    Science.gov (United States)

    El Halal, Shanise Lisie Mello; Colussi, Rosana; Deon, Vinícius Gonçalves; Pinto, Vânia Zanella; Villanova, Franciene Almeida; Carreño, Neftali Lenin Villarreal; Dias, Alvaro Renato Guerra; Zavareze, Elessandra da Rosa

    2015-11-20

    Starch and cellulose fibers were isolated from grains and the husk from barley, respectively. Biodegradable films of native starch or oxidized starches and glycerol with different concentrations of cellulose fibers (0%, 10% and 20%) were prepared. The films were characterized by morphological, mechanical, barrier, and thermal properties. Cellulose fibers isolated from the barley husk were obtained with 75% purity and high crystallinity. The morphology of the films of the oxidized starches, regardless of the fiber addition, was more homogeneous as compared to the film of the native starch. The addition of cellulose fibers in the films increased the tensile strength and decreased elongation. The water vapor permeability of the film of oxidized starch with 20% of cellulose fibers was lower than the without fibers. However the films with cellulose fibers had the highest decomposition with the initial temperature and thermal stability. The oxidized starch and cellulose fibers from barley have a good potential for use in packaging. The addition of cellulose fibers in starch films can contribute to the development of films more resistant that can be applied in food systems to maintain its integrity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. Oxygen permeability of nanocomposite-based polyolefin films; Permeabilidade do oxigenio em filmes nanocompositos poliolefinicos

    Energy Technology Data Exchange (ETDEWEB)

    Fujiyama-Novak, Jane H.; Amaral, Rafael A.; Ruffino, Vivianne; Habert, A. Claudio; Borges, Cristiano P., E-mail: jane@peq.coppe.ufrj.br [Coordenacao dos Programas de Pos-Graduacao em Engenharia (PEQ/COPPE/UFRJ), Rio de Janeiro, RJ (Brazil); Mano, Barbara [BRASKEM S.A., Duque de Caxias, RJ (Brazil)

    2015-07-01

    Polyethylene and polypropylene are vastly employed for packaging due to their high versatility and low cost. However, their films are permeable at different degree to small molecules like gases and the use of additives improves the barrier properties. Therefore, the aim of this work is to investigate the effect of organically modified montmorillonite on oxygen transport properties of PE and PP films. Nanocomposites were prepared by means of polymer dissolution in organic solvent and subsequent nanoparticle addition at 3, 5 and 10% (w/w). Scanning electron microscopy images of the films indicate the presence of microcavities and some agglomerated nanoclay. On the other hand, X-rays diffraction analysis shows clay in well-dispersed state independent of polyolefin type. Enhancement of oxygen barrier is achieved, but this property is dependent on the nanoclay content, polyolefin type and film morphology. (author)

  4. Graphene-based electrodes for enhanced organic thin film transistors based on pentacene.

    Science.gov (United States)

    Basu, Sarbani; Lee, Mu Chen; Wang, Yeong-Her

    2014-08-21

    This paper presents 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-pentacene) and pentacene-based organic thin film transistors (OTFTs) with monolayer graphene source-drain (S-D) electrodes. The electrodes are patterned using conventional photolithographic techniques combined with reactive ion etching. The monolayer graphene film grown by chemical vapor deposition on Cu foil was transferred on a Si dioxide surface using a polymer-supported transfer method to fabricate bottom-gate, bottom-contact OTFTs. The pentacene OTFTs with graphene S-D contacts exhibited superior performance with a mobility of 0.1 cm(2) V(-1) s(-1) and an on-off ratio of 10(5) compared with OTFTs with Au-based S-D contacts, which had a mobility of 0.01 cm(2) V(-1) s(-1) and an on-off ratio of 10(3). The crystallinity, grain size, and microscopic defects (or the number of layers of graphene films) of the TIPS-pentacene/pentacene films were analyzed by X-ray diffraction spectroscopy, atomic force microscopy, and Raman spectroscopy, respectively. The feasibility of using graphene as an S-D electrode in OTFTs provides an alternative material with high carrier injection efficiency, chemical stability, and excellent interface properties with organic semiconductors, thus exhibiting improved device performance of C-based electronic OTFTs at a reduced cost.

  5. Films based on protein isolated from croaker (Micropogonias furnieri) and palm oil.

    Science.gov (United States)

    Halal, Shanise Lisie Mello El; Zavareze, Elessandra da Rosa; Rocha, Meritaine da; Pinto, Vânia Zanella; Nunes, Michael Ramos; Luvielmo, Márcia de Mello; Prentice, Carlos

    2016-05-01

    The microstructure and the physical, mechanical, barrier and thermal properties of films based on different concentrations of protein isolated from croaker waste (CPI) and palm oil (PO) were analyzed. Films were elaborated by a casting technique using 2, 3 and 4 g CPI 100 g(-1) of a filmogenic solution and 0, 10 and 20 g of PO 100 g(-1) CPI. Microstructure of the film surfaces of CPI with PO showed no presence of lipid droplets dispersed in the filmogenic matrix, although a rough surface was present. Films with 3% and 4% CPI and 20% PO had the lowest rates of water vapor permeability. When there was an addition of PO to the reduced tensile strength of the films, regardless of the concentration of CPI, this addition reduced the elongation of films with 3% and 4% CPI; however, it did not influence films with 2% CPI, which did not differ from the control film (0% OP). Thermal analysis revealed that films with the highest PO percentage had a lower initial weight loss when compared with other films, due to higher hydrophobicity. The use of protein isolate obtained from fish residues of low commercial value and palm oil is viable for the production of biodegradable films because the latter constitute good barrier properties and thermal stability. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  6. Laser created thin films sensors based on Sn- and indium compounds

    Czech Academy of Sciences Publication Activity Database

    Myslík, V.; Vysloužil, F.; Vrňata, M.; Fryček, R.; Jelínek, Miroslav; Lančok, Ján

    2002-01-01

    Roč. 12, č. 2 (2002), s. 329-333 ISSN 1054-660X Institutional research plan: CEZ:AV0Z1010921 Keywords : PLD * Sn-based thin films * In-based thin films Subject RIV: BH - Optics, Masers, Lasers Impact factor: 0.798, year: 2002

  7. Moving beyond "Bookish Knowledge": Using Film-Based Assignments to Promote Deep Learning

    Science.gov (United States)

    Olson, Joann S.; Autry, Linda; Moe, Jeffry

    2016-01-01

    This article investigates the effectiveness of a film-based assignment given to adult learners in a graduate-level group counseling class. Semi-structured interviews were conducted with four students; data analysis suggested film-based assignments may promote deep approaches to learning (DALs). Participants indicated the assignment helped them…

  8. Aplicação de filmes proteicos à base de soro de leite Application of whey protein films

    Directory of Open Access Journals (Sweden)

    Cristiana Maria Pedroso Yoshida

    2009-06-01

    Full Text Available A eficiência da aplicação de filmes à base de proteínas de soro de leite foi avaliada em um sistema de embalagem que consistia em um pote plástico utilizando-se filmes de proteínas de soro de leite como fechamento superior. Pedaços de maçã foram embalados e armazenados à temperatura ambiente (25 °C e sob refrigeração (10 °C. Os filmes proteicos à base de soro de leite foram obtidos por três procedimentos distintos: por desnaturação térmica; com a incorporação de ácido esteárico (0,5%, em massa; e por modificação enzimática utilizando-se a transglutaminase microbiana (10U/g proteína, ACTIVA TG-B , a partir de uma formulação básica de 6,50% de proteína, 3,0% de plastificante (glicerol e pH 7,0. A integridade dos filmes após embalagem e durante armazenamento foi observada, medindo-se as propriedades mecânicas dos filmes. A permeabilidade ao vapor d'água foi avaliada pela perda de massa, teor de umidade, e variação de textura dos pedaços de maçã. Os resultados indicaram que os filmes apresentam uma barreira moderada à umidade, apresentando diferença entre potes com e sem coberturas de filmes. A permeabilidade ao oxigênio foi conferida pelo escurecimento enzimático das maçãs pela ação da enzima polifenoxidase, apresentando diferença em relação ao das amostras acondicionadas em atmosfera modificada com gás N2.The efficiency of whey protein films packaging was evaluated. The packaging system consisted of whey protein films closing the top extremity of synthetic plastic container. Slices of apple were packed and stored at room temperature (25 °C and at 10 °C. Modified atmosphere packaging (N2 gas flushing was studied to verify the oxygen permeability of the films. Whey protein films (6.5% of protein, 3.0% of glycerol, and pH 7.0 were obtained by thermal denaturation, emulsification (0.5% (w/w with stearic acid, and enzymatic modification (10U/g protein of transglutaminase, ACTIVA-TG. Mechanical

  9. Transparent Low Electrostatic Charge Films Based on Carbon Nanotubes and Polypropylene. Homopolymer Cast Films

    Directory of Open Access Journals (Sweden)

    Zoe Vineth Quiñones-Jurado

    2018-01-01

    Full Text Available Use of multi-wall carbon nanotubes (MWCNTs in external layers (A-layers of ABA-trilayer polypropylene films was investigated, with the purpose of determining intrinsic and extrinsic factors that could lead to antistatic behavior of transparent films. The incorporation of 0.01, 0.1, and 1 wt % of MWCTNs in the A-layers was done by dilution through the masterbatch method. Masterbatches were fabricated using isotactic polypropylene (iPP with different melt flow indexes 2.5, 34, and 1200 g/10 min, and using different ultrasound assist methods. It was found that films containing MWCNTs show surface electrical resistivity of 1012 and 1016 Ω/sq, regardless of the iPP melt flow index (MFI and masterbatch fabrication method. However, electrostatic charge was found to depend upon the iPP MFI, the ultrasound assist method and MWCNT concentration. A percolation electron transport mechanism was determined most likely responsible for this behavior. Optical properties for films containing MWCNTs do not show significant differences compared to the reference film at MWCNT concentrations below 0.1 wt %. However, an enhancement in brightness was observed, and it was attributed to ordered iPP molecules wrapping the MWCNTs. Bright transparent films with low electrostatic charge were obtained even for MWCNTs concentrations as low as 0.01 wt %.

  10. Physicochemical and microstructural characterization of gum tragacanth added whey protein based films.

    Science.gov (United States)

    Tonyali, Bade; Cikrikci, Sevil; Oztop, Mecit Halil

    2018-03-01

    Edible films of gum tragacanth (GT) with whey protein were fabricated to see how the incorporation of GT influenced whey protein based film properties. Whey protein isolate (WPI) was replaced with GT at different ratios as 0.5, 1, 1.5 and 2% of WPI. Optical, mechanical, permeability and microstructural properties, as well as moisture sorption and solubility behavior of films were measured. The findings indicated that combination of WPI and GT in film formulation led to less strength, more flexible, less soluble films with lower permeability to water and with higher opacity. The results suggested that the addition of GT to WPI could lead to obtain modified WPI based edible films with desirable properties. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Application of gamma irradiation on forming protein-based edible films

    International Nuclear Information System (INIS)

    Sabato, Susy Frey

    2000-01-01

    In the last decade considerable interest has been addressed to the development of protein-based edible films due to their application in the food industry, as a substitute to traditional plastic films. The use of soy and whey proteins to form those films has been investigated, using heat, chemical and enzymatic processes. Gamma irradiation was recently reported to form caseinate-based edible films, due to the increase of the cohesive strength of the proteins by the formation of cross-links. This work aimed to verify the role of the gamma irradiation in the process of forming edible films from soy protein isolate (SPI) alone and in complex mixtures, that is, mixed with whey protein isolate (WPI), with carbethoxymethyl cellulose (CMC) and with poly(vinyl)alcohol (PVA). Gamma irradiation treatment improved significantly the mechanical properties for all films. The mechanical behavior is strongly related to the formulation, showing synergy between the gamma irradiation and the CMC, mainly for SPI-based films. SPI-based films presented a trend to decrease the water vapor permeability values when irradiated. The CMC addition showed significant improvements on the permeability for films from SPI and from the mixture of SPI with WPI. (author)

  12. Soil burial biodegradation studies of palm oil-based UV-curable films

    International Nuclear Information System (INIS)

    Tajau, Rida; Salleh, Mek Zah; Salleh, Nik Ghazali Nik; Abdurahman, Mohamad Norahiman; Salih, Ashraf Mohammed; Fathy, Siti Farhana; Azman, Anis Asmi; Hamidi, Nur Amira

    2016-01-01

    The palm oil-based ultraviolet (uv)-curable films were subjected to an outdoor soil burial test to investigate the biodegradation under natural environment. The films were burial in the soil experiment plot at the Nuclear Malaysia’s Dengkil complex. The uv-curable films were synthesized from the epoxidized palm oil acrylated (EPOLA) resin and the polyurethane palm oil (POBUA) resin, respectively. Biodegradation tests are more specific to burial film in soil experiments for 12 months under natural conditions. The biodegradability of palm oil resin based uv-curable films were investigated and compared with the petrochemical resin based film. The films properties were compared with respect to properties of the thermal characteristic, the crystallinity, the morphology and the weight loss which are analyzed using the thermogravimetric analysis (TGA), the differential scanning calorimetry (DSC), the scanning electron microscope (SEM), an optical microscope and the weight loss of film calculation. These findings suggested that the palm oil-based uv-curable films show quite satisfactory biodegradation levels

  13. Soil burial biodegradation studies of palm oil-based UV-curable films

    Science.gov (United States)

    Tajau, Rida; Salleh, Mek Zah; Salleh, Nik Ghazali Nik; Abdurahman, Mohamad Norahiman; Salih, Ashraf Mohammed; Fathy, Siti Farhana; Azman, Anis Asmi; Hamidi, Nur Amira

    2016-01-01

    The palm oil-based ultraviolet (uv)-curable films were subjected to an outdoor soil burial test to investigate the biodegradation under natural environment. The films were burial in the soil experiment plot at the Nuclear Malaysia's Dengkil complex. The uv-curable films were synthesized from the epoxidized palm oil acrylated (EPOLA) resin and the polyurethane palm oil (POBUA) resin, respectively. Biodegradation tests are more specific to burial film in soil experiments for 12 months under natural conditions. The biodegradability of palm oil resin based uv-curable films were investigated and compared with the petrochemical resin based film. The films properties were compared with respect to properties of the thermal characteristic, the crystallinity, the morphology and the weight loss which are analyzed using the thermogravimetric analysis (TGA), the differential scanning calorimetry (DSC), the scanning electron microscope (SEM), an optical microscope and the weight loss of film calculation. These findings suggested that the palm oil-based uv-curable films show quite satisfactory biodegradation levels.

  14. Soil burial biodegradation studies of palm oil-based UV-curable films

    Energy Technology Data Exchange (ETDEWEB)

    Tajau, Rida, E-mail: rida@nuclearmalaysia.gov.my; Salleh, Mek Zah, E-mail: mekzah@nuclearmalaysia.gov.my; Salleh, Nik Ghazali Nik, E-mail: nik-ghazali@nuclearmalaysia.gov.my; Abdurahman, Mohamad Norahiman, E-mail: iman5031@yahoo.com [Division of Radiation Processing Technology, Malaysia Nuclear Agency, Bangi, 43000 Kajang, Selangor (Malaysia); Salih, Ashraf Mohammed, E-mail: ashraf.msalih@gmail.com [Department of Radiation Processing, Sudan Atomic Energy Commission, Khartoum, 1111 Sudan (Sudan); Fathy, Siti Farhana, E-mail: farhana811@hotmail.com [Laboratory of Molecular Biomedicine, Institute of Bioscience (IBS), Universiti Putra Malaysia (UPM), 43400 UPM, Serdang, Selangor (Malaysia); Azman, Anis Asmi, E-mail: anisasmi18@gmail.com; Hamidi, Nur Amira, E-mail: amirahamidi93@yahoo.com [School of Chemical Sciences, Universiti Sains Malaysia (USM), 11800 USM, Pulau Pinang (Malaysia)

    2016-01-22

    The palm oil-based ultraviolet (uv)-curable films were subjected to an outdoor soil burial test to investigate the biodegradation under natural environment. The films were burial in the soil experiment plot at the Nuclear Malaysia’s Dengkil complex. The uv-curable films were synthesized from the epoxidized palm oil acrylated (EPOLA) resin and the polyurethane palm oil (POBUA) resin, respectively. Biodegradation tests are more specific to burial film in soil experiments for 12 months under natural conditions. The biodegradability of palm oil resin based uv-curable films were investigated and compared with the petrochemical resin based film. The films properties were compared with respect to properties of the thermal characteristic, the crystallinity, the morphology and the weight loss which are analyzed using the thermogravimetric analysis (TGA), the differential scanning calorimetry (DSC), the scanning electron microscope (SEM), an optical microscope and the weight loss of film calculation. These findings suggested that the palm oil-based uv-curable films show quite satisfactory biodegradation levels.

  15. Formulation of chitosan-based ciprofloxacin and diclofenac film for ...

    African Journals Online (AJOL)

    Purpose: This study was designed to develop and evaluate chitosan films containing ciprofloxacin and diclofenac sodium for the topical treatment of periodontitis. Methods: Chitosan films containing ciprofloxacin alone and in combination with diclofenac sodium were prepared by solvent casting method. Some of the ...

  16. Thin-film chemical sensors based on electron tunneling

    Science.gov (United States)

    Khanna, S. K.; Lambe, J.; Leduc, H. G.; Thakoor, A. P.

    1985-01-01

    The physical mechanisms underlying a novel chemical sensor based on electron tunneling in metal-insulator-metal (MIM) tunnel junctions were studied. Chemical sensors based on electron tunneling were shown to be sensitive to a variety of substances that include iodine, mercury, bismuth, ethylenedibromide, and ethylenedichloride. A sensitivity of 13 parts per billion of iodine dissolved in hexane was demonstrated. The physical mechanisms involved in the chemical sensitivity of these devices were determined to be the chemical alteration of the surface electronic structure of the top metal electrode in the MIM structure. In addition, electroreflectance spectroscopy (ERS) was studied as a complementary surface-sensitive technique. ERS was shown to be sensitive to both iodine and mercury. Electrolyte electroreflectance and solid-state MIM electroreflectance revealed qualitatively the same chemical response. A modified thin-film structure was also studied in which a chemically active layer was introduced at the top Metal-Insulator interface of the MIM devices. Cobalt phthalocyanine was used for the chemically active layer in this study. Devices modified in this way were shown to be sensitive to iodine and nitrogen dioxide. The chemical sensitivity of the modified structure was due to conductance changes in the active layer.

  17. Characterization of AZO and Ag based films prepared by RF magnetron sputtering

    International Nuclear Information System (INIS)

    Miao, Dagang; Jiang, Shouxiang; Zhao, Hongmei; Shang, Songmin; Chen, Zhuoming

    2014-01-01

    Highlights: • Highly infrared reflective AZO and Ag based films were prepared. • Ag showed better crystallization on AZO film than on glass substrate. • Infrared reflection rate was inversely proportional to the film sheet resistance. • Film with infrared reflection of 97% in FIR region was acquired. - Abstract: Ag, AZO/Ag, Ag/AZO and AZO/Ag/AZO films were prepared on glass substrates by radio frequency (RF) magnetron sputtering technology. The prepared films were systematically investigated by X-ray Diffraction (XRD), Atomic Force Microscopy (AFM), UV–visible spectrophotometer, a four-point probe system and Fourier Transform Infrared Spectroscopy. The results indicated that Ag inner layer starts forming a continuous film at the thickness of 10 nm and Ag layer presents superior crystallization on AZO substrate than that on glass substrate. The continuous Ag inner layer film provided the highest average visible transmittance of 85.4% (AZO/Ag/AZO). The lowest sheet resistance of 3.21 Ω/sq and the highest infrared reflection rate of 97% in FIR region can be obtained on AZO/Ag (15 nm)/AZO film. The high infrared reflection property of the AZO/Ag/AZO coating makes it a promising candidate for solar control films

  18. Pectin- and gelatin-based film: effect of gamma irradiation on the mechanical properties and biodegradation

    Energy Technology Data Exchange (ETDEWEB)

    Jo, Cheorun; Kang, Hojin; Lee, Na Young; Kwon, Joong Ho; Byun, Myung Woo E-mail: mwbyun@kaeri.re.kr

    2005-04-01

    Agricultural by-products, pectin and gelatin, were used to prepare a biodegradable film. The film casting solution including the pectin and gelatin was irradiated at 0, 10, 20, and 30 kGy to investigate the irradiation effect on the mechanical properties of the film. The tensile strength of the 10 kGy-irradiated film was the highest among the treatments but the elongation at break, water vapour permeability, and swelling ratio were the lowest. Hunter color L*- and a*-values decreased but the b*-value increased as the irradiation dose increased. The total organic carbon content produced from the Paenibacillus polymyxa and Pseudomonas aeruginosa also showed that the film of 10 kGy-irradiated was lower than those of 0, 20, and 30 kGy-irradiated films. In conclusion, irradiation of the film casting solution at 10 kGy increased the mechanical properties of the pectin and gelatin based film. To manufacture the film by agricultural by-products, however, the irradiation dose of the film casting solution should be determined to achieve better mechanical properties.

  19. Multifunctional thick-film structures based on spinel ceramics for environment sensors

    International Nuclear Information System (INIS)

    Vakiv, M; Hadzaman, I; Klym, H; Shpotyuk, O; Brunner, M

    2011-01-01

    Temperature sensitive thick films based on spinel-type NiMn 2 O 4 -CuMn 2 O 4 -MnCo 2 O 4 manganites with p- and p + -types of electrical conductivity and their multilayer p + -p structures were studied. These thick-film elements possess good electrophysical characteristics before and after long-term ageing test at 170 deg. C. It is shown that degradation processes connected with diffusion of metallic Ag into film grain boundaries occur in one-layer p-and p + -conductive films. Some part of the p + -p structures were of high stability, the relative electrical drift being no more than 1 %.

  20. Properties of planar structures based on Policluster films of diamond and AlN

    Science.gov (United States)

    Belyanin, A. F.; Luchnikov, A. P.; Nalimov, S. A.; Bagdasarian, A. S.

    2018-01-01

    AlN films doped with zinc were grown on Si substrates by RF magnetron reactive sputtering of a compound target. Policluster films of diamond doped with boron were formed on layered Si/AlN substrates from the gas phase hydrogen and methane, activated arc discharge. By electron microscopy, X-ray diffraction and Raman spectroscopy the composition and structure of synthetic policluster films of diamond and AlN films were studied. Photovoltaic devices based on the AlN/PFD layered structure are presented.

  1. Copper zinc tin sulfide-based thin film solar cells

    CERN Document Server

    Ito, Kentaro

    2014-01-01

    Beginning with an overview and historical background of Copper Zinc Tin Sulphide (CZTS) technology, subsequent chapters cover properties of CZTS thin films, different preparation methods of CZTS thin films, a comparative study of CZTS and CIGS solar cell, computational approach, and future applications of CZTS thin film solar modules to both ground-mount and rooftop installation. The semiconducting compound (CZTS) is made up earth-abundant, low-cost and non-toxic elements, which make it an ideal candidate to replace Cu(In,Ga)Se2 (CIGS) and CdTe solar cells which face material scarcity and tox

  2. Tribological performance of ultrathin diamond-like carbon films prepared by plasma-based ion implantation

    International Nuclear Information System (INIS)

    Liao, J X; Li, E Q; Tian, Z; Pan, X F; Xu, J; Jin, L; Yang, H G

    2008-01-01

    Ultrathin diamond-like carbon (DLC) films with thicknesses of 5-60 nm have been prepared on Si by plasma-based ion implantation. Raman spectrum and x-ray photoelectron spectroscopy (XPS) show that these DLC films present high sp 3 /sp 2 ratios. XPS also displays that each DLC film firmly adheres to the Si substrate owing to a C-Si transition layer. Atomic force microscopy shows that the DLC films are smooth and compact with average roughness (R a ) of about 0.25 nm. Sliding friction experiments reveal that these DLC films show significantly improved tribological performance. With increase of DLC film thickness, the sp 3 /sp 2 ratio increases, the roughness decreases, the hardness increases, the adhesive wear lightens and thereby the tribological performance becomes enhanced. Also, the effects of the applied load and the reciprocating frequency on the tribological performance are discussed

  3. Effect of carboxymethyl cellulose concentration on physical properties of biodegradable cassava starch-based films

    Directory of Open Access Journals (Sweden)

    Sriburi Pensiri

    2011-02-01

    Full Text Available Abstract Background Cassava starch, the economically important agricultural commodity in Thailand, can readily be cast into films. However, the cassava starch film is brittle and weak, leading to inadequate mechanical properties. The properties of starch film can be improved by adding plasticizers and blending with the other biopolymers. Results Cassava starch (5%w/v based films plasticized with glycerol (30 g/100 g starch were characterized with respect to the effect of carboxymethyl cellulose (CMC concentrations (0, 10, 20, 30 and 40%w/w total solid and relative humidity (34 and 54%RH on the mechanical properties of the films. Additionally, intermolecular interactions were determined by Fourier transform infrared spectroscopy (FT-IR, melting temperature by differential scanning calorimetry (DSC, and morphology by scanning electron microscopy (SEM. Water solubility of the films was also determined. Increasing concentration of CMC increased tensile strength, reduced elongation at break, and decreased water solubility of the blended films. FT-IR spectra indicated intermolecular interactions between cassava starch and CMC in blended films by shifting of carboxyl (C = O and OH groups. DSC thermograms and SEM micrographs confirmed homogeneity of cassava starch-CMC films. Conclusion The addition of CMC to the cassava starch films increased tensile strength and reduced elongation at break of the blended films. This was ascribed to the good interaction between cassava starch and CMC. Cassava starch-CMC composite films have the potential to replace conventional packaging, and the films developed in this work are suggested to be suitable for low moisture food and pharmaceutical products.

  4. A comparative chemical network study of HWCVD deposited amorphous silicon and carbon based alloys thin films

    Energy Technology Data Exchange (ETDEWEB)

    Swain, Bibhu P., E-mail: bibhuprasad.swain@gmail.com [Centre for Materials Science and Nanotechnology, Sikkim Manipal Institute of Technology, Majitar, Rangpo Sikkim (India); Swain, Bhabani S.; Hwang, Nong M. [Thin Films and Microstructure Laboratory, Department of Materials Science and Engineering, Seoul National University, Seoul (Korea, Republic of)

    2014-03-05

    Highlights: • a-SiC:H, a-SiN:H, a-C:H and a-SiCN:H films were deposited by hot wire chemical vapor deposition. • Evolution of microstructure of a-SiCN:H films deposited at different NH{sub 3} flow rate were analyzed. • The chemical network of Si and C based alloys were studied by FTIR and Raman spectroscopy. -- Abstract: Silicon and carbon based alloys were deposited by hot wire chemical vapor deposition (HWCVD). The microstructure and chemical bonding of these films were characterized by field emission scanning electron microscopy, Fourier transform infrared spectroscopy and Raman spectroscopy. The electron microscopy revealed various microstructures were observed for a-C:H, a-SiC:H, a-SiN:H, a-CN:H and a-SiCN:H films. The microstructure of SiN:H films showed agglomerate spherical grains while a-C:H films showed more fractal surface with branched microstructure. However, a-SiC:H, a-CN:H and a-SiCN:H indicated uniform but intermediate surface fractal microstructure. A series of a-SiCN:H films were deposited with variation of NH{sub 3} flow rate. The nitrogen incorporation in a-SiCN:H films alter the carbon network from sp{sup 2} to sp{sup 3} bonding The detail chemical bonding of amorphous films was analyzed by curve fitting method.

  5. Physical Characteristics of Chitosan Based Film Modified With Silica and Polyethylene Glycol

    Directory of Open Access Journals (Sweden)

    F. Widhi Mahatmanti

    2014-07-01

    Full Text Available Recently, development of film materials is focused on finding the films with high chemical and physical stabilities. Organic based material such as chitosan produces films with low physical stability, and hence addition of inorganic materials necessary. In this research, the effect of silica and polyethylene glycol (PEG addition on the properties of chitosan based films has been investigated. Precursors used to produce films included chitosan with the deacetylation degree of 83% and sodium silicate solution as the silica source. A simple synthesis in a one-pot process was carried out by mixing 1%(w of chitosan solution in 2%(v/v acetate acid and sodium silicate solution (27% SiO2 in various composition ratios and casting the solution on a glass dish. The tensile strength and percentage of elongation decrease with increasing the silica content. The tensile strength tends to decline with addition of PEG, but the elongation percentage of the film increases. Hydrophilicity of the film decreases with the addition of silica and increases with the addition of PEG. The addition of silica and PEG does not change significantly the morphology of the film and functional groups indicating the domination of physical interaction among active sites in the film components.

  6. Transparent indium zinc oxide thin films used in photovoltaic cells based on polymer blends

    International Nuclear Information System (INIS)

    Besleaga, Cristina; Ion, L.; Ghenescu, Veta; Socol, G.; Radu, A.; Arghir, Iulia; Florica, Camelia; Antohe, S.

    2012-01-01

    Indium zinc oxide (IZO) thin films were obtained using pulsed laser deposition. The samples were prepared by ablation of targets with In concentrations, In/(In + Zn), of 80 at.%, at low substrate temperatures under reactive atmosphere. IZO films were used as transparent electrodes in polymer-based – poly(3-hexylthiophene) and 1-(3-methoxycarbonyl)-propyl-1-phenyl-(6,6)C61 1:1 blend – photovoltaic cells. The action spectra measurements revealed that IZO-based photovoltaic structures have performances comparable with those using indium–tin–oxide as transparent electrode. - Highlights: ► Indium zinc oxide films were grown by pulsed laser deposition at room temperature. ► The films had large free carrier density and reasonably high mobility. ► These films fit for transparent electrodes in polymer-based photovoltaic cells.

  7. Chemical solution deposition of LaMnO3-based films for coated conductors

    International Nuclear Information System (INIS)

    Shi, D Q; Zhu, X B; Kim, J H; Wang, L; Zeng, R; Dou, S X; Lei, H C; Sun, Y P

    2008-01-01

    LaMnO 3 -based films were prepared using the chemical solution deposition method. It was found that the films on perovskite oxide single crystal substrates are highly (h00)-oriented when the annealing atmosphere is oxygen or air; however, when the substrate is yttrium-stabilized ZrO 2 , only the La 1-x Na x MnO 3 films are highly (h00)-oriented, and other LaMnO 3 -based films are (110)-oriented. Under a reducing annealing atmosphere, the atmosphere must be wet in order to create a suitable oxygen partial pressure to crystallize the LaMnO 3 -based films. After annealing under a wet reducing atmosphere the LaMnO 3 -based films are (110)-oriented when the films are directly deposited on Ni tapes; however, when SrTiO 3 -buffered Ni tapes are used, the LaMnO 3 films are (h00)-oriented, which is suitable for subsequent growth of YBCO. The results suggest that it is possible to tune the orientation of buffer layers using suitable templates, which can widen the selection of buffer layers for coated conductors in the all metallorganic deposition approach

  8. ZnO-Based Transparent Conductive Thin Films: Doping, Performance, and Processing

    International Nuclear Information System (INIS)

    Liu, Y.; Li, Y.; Zeng, H.

    2013-01-01

    ZnO-based transparent conductive thin films have attracted much attention as a promising substitute material to the currently used indium-tin-oxide thin films in transparent electrode applications. However, the detailed function of the dopants, acting on the electrical and optical properties of ZnO-based transparent conductive thin films, is not clear yet, which has limited the development and practical applications of ZnO transparent conductive thin films. Growth conditions such as substrate type, growth temperature, and ambient atmosphere all play important roles in structural, electrical, and optical properties of films. This paper takes a panoramic view on properties of ZnO thin films and reviews the very recent works on new, efficient, low-temperature, and high-speed deposition technologies. In addition, we highlighted the methods of producing ZnO-based transparent conductive film on flexible substrate, one of the most promising and rapidly emerging research areas. As optimum-processing-parameter conditions are being obtained and their influencing mechanism is becoming clear, we can see that there will be a promising future for ZnO-based transparent conductive films.

  9. DNA hybridization sensor based on pentacene thin film transistor.

    Science.gov (United States)

    Kim, Jung-Min; Jha, Sandeep Kumar; Chand, Rohit; Lee, Dong-Hoon; Kim, Yong-Sang

    2011-01-15

    A DNA hybridization sensor using pentacene thin film transistors (TFTs) is an excellent candidate for disposable sensor applications due to their low-cost fabrication process and fast detection. We fabricated pentacene TFTs on glass substrate for the sensing of DNA hybridization. The ss-DNA (polyA/polyT) or ds-DNA (polyA/polyT hybrid) were immobilized directly on the surface of the pentacene, producing a dramatic change in the electrical properties of the devices. The electrical characteristics of devices were studied as a function of DNA immobilization, single-stranded vs. double-stranded DNA, DNA length and concentration. The TFT device was further tested for detection of λ-phage genomic DNA using probe hybridization. Based on these results, we propose that a "label-free" detection technique for DNA hybridization is possible through direct measurement of electrical properties of DNA-immobilized pentacene TFTs. Copyright © 2010 Elsevier B.V. All rights reserved.

  10. Nanoparticulate platinum films on gold using dendrimer-based wet ...

    Indian Academy of Sciences (India)

    Central Electrochemical Research Institute, Karaikudi 630 006, India. E-mail: ... deposition methods for applications involving thin films, e.g., catalysis. Deposition of platinum .... The spectrum recorded at 0.3 V shows a mixed control behaviour ...

  11. Comparative Review on Thin Film Growth of Iron-Based Superconductors

    Directory of Open Access Journals (Sweden)

    Yoshinori Imai

    2017-07-01

    Full Text Available Since the discovery of the novel iron-based superconductors, both theoretical and experimental studies have been performed intensively. Because iron-based superconductors have a smaller anisotropy than high-Tc cuprates and a high superconducting transition temperature, there have been a lot of researchers working on the film fabrication of iron-based superconductors and their application. Accordingly, many novel features have been reported in the films of iron-based superconductors, for example, the fabrication of the epitaxial film with a higher Tc than bulk samples, the extraction of the metastable phase which cannot be obtained by the conventional solid state reaction, and so on. In this paper, we review the progress of research on thin film fabrications of iron-based superconductors, especially the four categories: LnFeAs(O,F (Ln = Lanthanide, AEFe2As2 (AE = Alkaline-earth metal, FeCh (Ch = Chalcogen, and FeSe monolayer. Furthermore, we focus on two important topics in thin films of iron-based superconductors; one is the substrate material for thin film growth on the iron-based superconductors, and the other is the whole phase diagram in FeSe1-xTex which can be obtained only by using film-fabrication technique.

  12. Characterization of polymer, DNA-based, and silk thin film resistivities and of DNA-based films prepared for enhanced electrical conductivity

    Science.gov (United States)

    Yaney, Perry P.; Ouchen, Fahima; Grote, James G.

    2009-08-01

    DC resistivity studies were carried out on biopolymer films of DNA-CTMA and silk fibroin, and on selected traditional polymer films, including PMMA and APC. Films of DNA-CTMA versus molecular weight and with conductive dopants PCBM, BAYTRON P and ammonium tetrachloroplatinate are reported. The films were spin coated on glass slides configured for measurements of volume dc resistance. The measurements used the alternating polarity method to record the applied voltage-dependent current independent of charging and background currents. The Arrhenius equation plus a constant was fitted to the conductivity versus temperature data of the polymers and the non-doped DNA-based biopolymers with activation energies ranging from 0.8 to 1.4 eV.

  13. Edible antimicrobial films based on microencapsulated lemongrass oil.

    Science.gov (United States)

    Bustos C, Rubén O; Alberti R, Francesca V; Matiacevich, Silvia B

    2016-01-01

    Edible films and coatings have been proposed as viable alternatives for the preservation of fresh food such as fruit, meat, fish and cheese. They can be designed to contain natural antioxidants, vitamins and antimicrobials in order to extend shelf life of the product keeping the natural sensorial properties. Essential oils have been targeted as potential active principles for edible films and coatings given their well-recognized antioxidant, antimicrobial and sensory properties. In the present work, lemongrass oil (LMO) microcapsules were prepared by the emulsification-separation method using sodium caseinate as wall material. Microcapsules had an average size of 22 μm and contained over 51 % oil in their nucleus. The release kinetics of the LMO components was studied for both, microcapsules and microcapsule containing films. Experimental data for the controlled release of LMO components showed good correlation with Peppas and Weibull models. The effect of the alginate matrix on the release parameters of the mathematical models could be detected by the modification of the b constant of the Weibull equation which changed from 0.167 for the microcapsules to 0.351 for the films. Films containing LMO at concentrations of 1250, 2500 and 5000 ppm were able to inhibit growth of Escherichia coli ATCC 25922 and Listeria monocytogenes ISP 65-08 in liquid cultures. A possible future application of these films for shelf life extension of fresh food is discussed.

  14. Antimicrobial Films Based on Chitosan and Methylcellulose Containing Natamycin for Active Packaging Applications

    Directory of Open Access Journals (Sweden)

    Serena Santonicola

    2017-10-01

    Full Text Available Biodegradable polymers are gaining interest as antimicrobial carriers in active packaging. In the present study, two active films based on chitosan (1.5% w/v and methylcellulose (3% w/v enriched with natamycin were prepared by casting. The antimicrobial’s release behavior was evaluated by immersion of the films in 95% ethanol (v/v at different temperatures. The natamycin content in the food simulant was determined by reversed-high performance liquid chromatography with diode-array detection (HPLC-DAD. The apparent diffusion (DP and partition (KP/S coefficients were calculated using a mathematical model based on Fick’s Second Law. Results showed that the release of natamycin from chitosan based film (DP = 3.61 × 10−13 cm2/s was slower, when compared with methylcellulose film (DP = 3.20 × 10−8 cm2/s at the same temperature (p < 0.05. To evaluate the antimicrobial efficiency of active films, cheese samples were completely covered with the films, stored at 20 °C for 7 days, and then analyzed for moulds and yeasts. Microbiological analyses showed a significant reduction in yeasts and moulds (7.91 log CFU/g in samples treated with chitosan active films (p < 0.05. The good compatibility of natamycin with chitosan, the low Dp, and antimicrobial properties suggested that the film could be favorably used in antimicrobial packagings.

  15. Extraction of agar from Gelidium sesquipedale (Rhodopyta) and surface characterization of agar based films.

    Science.gov (United States)

    Guerrero, P; Etxabide, A; Leceta, I; Peñalba, M; de la Caba, K

    2014-01-01

    The chemical structure of the agar obtained from Gelidium sesquipedale (Rhodophyta) has been determined by (13)C nuclear magnetic resonance ((13)C NMR) and Fourier transform infrared spectroscopy (FTIR). Agar (AG) films with different amounts of soy protein isolate (SPI) were prepared using a thermo-moulding method, and transparent and hydrophobic films were obtained and characterized. FTIR analysis provided a detailed description of the binding groups present in the films, such as carboxylic, hydroxyl and sulfonate groups, while the surface composition was examined using X-ray photoelectron spectroscopy (XPS). The changes observed by FTIR and XPS spectra suggested interactions between functional groups of agar and SPI. This is a novel approach to the characterization of agar-based films and provides knowledge about the compatibility of agar and soy protein for further investigation of the functional properties of biodegradable films based on these biopolymers. Copyright © 2013 Elsevier Ltd. All rights reserved.

  16. Poly(lactic acid (PLA Based Tear Resistant and Biodegradable Flexible Films by Blown Film Extrusion

    Directory of Open Access Journals (Sweden)

    Norma Mallegni

    2018-01-01

    Full Text Available Poly(lactic acid (PLA was melt mixed in a laboratory extruder with poly(butylene adipate-co-terephthalate (PBAT and poly(butylene succinate (PBS in the presence of polypropylene glycol di glycidyl ether (EJ400 that acted as both plasticizer and compatibilizer. The process was then scaled up in a semi-industrial extruder preparing pellets having different content of a nucleating agent (LAK. All of the formulations could be processed by blowing extrusion and the obtained films showed mechanical properties dependent on the LAK content. In particular the tearing strength showed a maximum like trend in the investigated composition range. The films prepared with both kinds of blends showed a tensile strength in the range 12–24 MPa, an elongation at break in the range 150–260% and a significant crystallinity.

  17. Poly(lactic acid) (PLA) Based Tear Resistant and Biodegradable Flexible Films by Blown Film Extrusion

    OpenAIRE

    Norma Mallegni; Thanh Vu Phuong; Maria-Beatrice Coltelli; Patrizia Cinelli; Andrea Lazzeri

    2018-01-01

    Poly(lactic acid) (PLA) was melt mixed in a laboratory extruder with poly(butylene adipate-co-terephthalate) (PBAT) and poly(butylene succinate) (PBS) in the presence of polypropylene glycol di glycidyl ether (EJ400) that acted as both plasticizer and compatibilizer. The process was then scaled up in a semi-industrial extruder preparing pellets having different content of a nucleating agent (LAK). All of the formulations could be processed by blowing extrusion and the obtained films showed me...

  18. Removable polytetrafluoroethylene template based epitaxy of ferroelectric copolymer thin films

    Science.gov (United States)

    Xia, Wei; Chen, Qiusong; Zhang, Jian; Wang, Hui; Cheng, Qian; Jiang, Yulong; Zhu, Guodong

    2018-04-01

    In recent years ferroelectric polymers have shown their great potentials in organic and flexible electronics. To meet the requirements of high-performance and low energy consumption of novel electronic devices and systems, structural and electrical properties of ferroelectric polymer thin films are expected to be further optimized. One possible way is to realize epitaxial growth of ferroelectric thin films via removable high-ordered polytetrafluoroethylene (PTFE) templates. Here two key parameters in epitaxy process, annealing temperature and applied pressure, are systematically studied and thus optimized through structural and electrical measurements of ferroelectric copolymer thin films. Experimental results indicate that controlled epitaxial growth is realized via suitable combination of both parameters. Annealing temperature above the melting point of ferroelectric copolymer films is required, and simultaneously moderate pressure (around 2.0 MPa here) should be applied. Over-low pressure (around 1.0 MPa here) usually results in the failure of epitaxy process, while over-high pressure (around 3.0 MPa here) often results in residual of PTFE templates on ferroelectric thin films.

  19. Fabrication and nano-imprintabilities of Zr-, Pd- and Cu-based glassy alloy thin films

    International Nuclear Information System (INIS)

    Takenaka, Kana; Saidoh, Noriko; Nishiyama, Nobuyuki; Inoue, Akihisa

    2011-01-01

    With the aim of investigating nano-imprintability of glassy alloys in a film form, Zr 49 Al 11 Ni 8 Cu 32 , Pd 39 Cu 29 Ni 13 P 19 and Cu 38 Zr 47 Al 9 Ag 6 glassy alloy thin films were fabricated on Si substrate by a magnetron sputtering method. These films exhibit a very smooth surface, a distinct glass transition phenomenon and a large supercooled liquid region of about 80 K, which are suitable for imprinting materials. Moreover, thermal nano-imprintability of these obtained films is demonstrated by using a dot array mold with a dot diameter of 90 nm. Surface observations revealed that periodic nano-hole arrays with a hole diameter of 90 nm were successfully imprinted on the surface of these films. Among them, Pd-based glassy alloy thin film indicated more precise pattern imprintability, namely, flatter residual surface plane and sharper hole edge. It is said that these glassy alloy thin films, especially Pd-based glassy alloy thin film, are one of the promising materials for fabricating micro-machines and nano-devices by thermal imprinting.

  20. Gallic Acid as an Oxygen Scavenger in Bio-Based Multilayer Packaging Films.

    Science.gov (United States)

    Pant, Astrid F; Sängerlaub, Sven; Müller, Kajetan

    2017-05-03

    Oxygen scavengers are used in food packaging to protect oxygen-sensitive food products. A mixture of gallic acid (GA) and sodium carbonate was used as an oxygen scavenger (OSc) in bio-based multilayer packaging films produced in a three-step process: compounding, flat film extrusion, and lamination. We investigated the film surface color as well as oxygen absorption at different relative humidities (RHs) and temperatures, and compared the oxygen absorption of OSc powder, monolayer films, and multilayer films. The films were initially brownish-red in color but changed to greenish-black during oxygen absorption under humid conditions. We observed a maximum absorption capacity of 447 mg O₂/g GA at 21 °C and 100% RH. The incorporation of GA into a polymer matrix reduced the rate of oxygen absorption compared to the GA powder because the polymer acted as a barrier to oxygen and water vapor diffusion. As expected, the temperature had a significant effect on the initial absorption rate of the multilayer films; the corresponding activation energy was 75.4 kJ/mol. Higher RH significantly increased the oxygen absorption rate. These results demonstrate for the first time the production and the properties of a bio-based multilayer packaging film with GA as the oxygen scavenger. Potential applications include the packaging of food products with high water activity (a w > 0.86).

  1. A Web-based multimedia collaboratory. Empirical work studies in film archives

    DEFF Research Database (Denmark)

    Pejtersen, A.M.; Albrechtsen, H.; Cleal, B.

    2001-01-01

    and interfaces for collaborative work and content-based access to digital repositories for film archives, researchers and end-users. This report is based on empirical analysis of three film archives inGermany, Austria and the Czech Republic, and seeks to elicit the user needs for a collaboratory in this domain....... Both the collection and analysis of data have been organised according to principles of Cognitive Work Analysis (CWA) as pioneered at Risø (cf.Rasmussen, Pejtersen and Goodstein 1994). Research based work on individual film projects is, due to international distribution and multiple versions, dependent......The Collaboratory for Annotation, Indexing and Retrieval of Digitized Historical Archive Material (Collate) is intended to foster and support collaboration on research, cultural mediation and preservation of films through a distributed multimediarepository. The tool will provide web-based tools...

  2. High-performance piezoelectric thick film based energy harvesting micro-generators for MEMS

    DEFF Research Database (Denmark)

    Zawada, Tomasz; Hansen, Karsten; Lou-Moeller, Rasmus

    2010-01-01

    and are transformed by the energy harvesting micro-generator into usable electrical signal. The micro-generator comprises a silicon cantilever with integrated InSensor® TF2100 PZT thick film deposited using screen-printing. The output power versus frequency and electrical load has been investigated. Furthermore......, devices based on modified, pressure treated thick film materials have been tested and compared with the commercial InSensor® TF2100 PZT thick films. It has been found that the structures based on the pressure treated materials exhibit superior properties in terms of energy output....

  3. Chitosan-based films composites for wound healing purposes

    International Nuclear Information System (INIS)

    Alves, Natali de O.; Silva, Gabriela T. da; Schulz, Gracelie A.S.; Fajardo, Andre R.

    2015-01-01

    Chitosan has been extensively applied in the developing of biomaterials due to its desirable good physico-chemical and biological properties. According to this, here films composite of chitosan, poly(vinyl alcohol) and bovine bone powder were prepared by casting willing to be applied in wound healing purposes. Moreover, the first step was the developing of a suitable method to obtain bovine bone powder, which was utilized here as filler. All the materials and films were fully characterized by FTIR, DRX and thermal analysis. Water uptake capacity was measured by swelling assays. (author)

  4. Study of a Particle Based Films Cure Process by High-Frequency Eddy Current Spectroscopy

    Directory of Open Access Journals (Sweden)

    Iryna Patsora

    2016-12-01

    Full Text Available Particle-based films are today an important part of various designs and they are implemented in structures as conductive parts, i.e., conductive paste printing in the manufacture of Li-ion batteries, solar cells or resistive paste printing in IC. Recently, particle based films were also implemented in the 3D printing technique, and are particularly important for use in aircraft, wind power, and the automotive industry when incorporated onto the surface of composite structures for protection against damages caused by a lightning strike. A crucial issue for the lightning protection area is to realize films with high homogeneity of electrical resistance where an in-situ noninvasive method has to be elaborated for quality monitoring to avoid undesirable financial and time costs. In this work the drying process of particle based films was investigated by high-frequency eddy current (HFEC spectroscopy in order to work out an automated in-situ quality monitoring method with a focus on the electrical resistance of the films. Different types of particle based films deposited on dielectric and carbon fiber reinforced plastic substrates were investigated in the present study and results show that the HFEC method offers a good opportunity to monitor the overall drying process of particle based films. Based on that, an algorithm was developed, allowing prediction of the final electrical resistance of the particle based films throughout the drying process, and was successfully implemented in a prototype system based on the EddyCus® HFEC device platform presented in this work. This prototype is the first solution for a portable system allowing HFEC measurement on huge and uneven surfaces.

  5. Ratiometric glucose sensing based on fluorescent oxygen films and glucose oxidase

    Directory of Open Access Journals (Sweden)

    Fengyu Su

    2017-06-01

    Full Text Available A new two-layer sensor film was constructed for sensing glucose based on glucose oxidase and oxygen sensing material. The first layer of film containing the oxygen sensor and intra-reference material was polymerized, then the second layer of glucose oxidase and glutaraldehyde was formed on the oxygen sensor layer. The two-layer sensor film has a resolution up to 0.05 mM and a detection range from 0 to 5 mM to glucose. The effects of pH and temperature on the sensing performance were systematically investigated. The selective detection of glucose among other monosaccharides, such as fructose, mannose and galactose indicated that the sensing film has excellent selectivity. The prepared sensor was successfully applied for glucose sample detection of glucose concentration in artificial tears. Keywords: Glucose sensor, Glucose oxidase, Fluorescence, Oxygen film, Diabetes

  6. Mechanical and thermal properties of irradiated films based on Tilapia (Oreochromis niloticus) proteins

    Energy Technology Data Exchange (ETDEWEB)

    Sabato, S.F. [Radiation Technology Center, IPEN-CNEN/SP, Av. Lineu Prestes 2242, 05508 900 Sao Paulo, SP (Brazil)], E-mail: sfsabato@ipen.br; Nakamurakare, N.; Sobral, P.J.A. [Food Engineering Department, ZEA/FZEA/USP, Av. Duque de Caxias Norte 225, 13635 900 Pirassununga, SP (Brazil)

    2007-11-15

    Proteins are considered potential material in natural films as alternative to traditional packaging. When gamma radiation is applied to protein film forming solution it resulted in an improvement in mechanical properties of whey protein films. The objective of this work was the characterization of mechanical and thermal properties of irradiated films based on muscle proteins from Nile Tilapia (Oreochromis niloticus). The films were prepared according to a casting technique with two levels of plasticizer: 25% and 45% glycerol and irradiated in electron accelerator type Radiation Dynamics, 0.550 MeV at dose range from 0 to 200 kGy. Thermal properties and mechanical properties were determined using a differential scanning calorimeter and a texture analyzer, respectively. Radiation from electron beam caused a slightly increase on its tensile strength characteristic at 100 kGy, while elongation value at this dose had no reduction.

  7. Mechanical and thermal properties of irradiated films based on Tilapia (Oreochromis niloticus) proteins

    International Nuclear Information System (INIS)

    Sabato, S.F.; Nakamurakare, N.; Sobral, P.J.A.

    2007-01-01

    Proteins are considered potential material in natural films as alternative to traditional packaging. When gamma radiation is applied to protein film forming solution it resulted in an improvement in mechanical properties of whey protein films. The objective of this work was the characterization of mechanical and thermal properties of irradiated films based on muscle proteins from Nile Tilapia (Oreochromis niloticus). The films were prepared according to a casting technique with two levels of plasticizer: 25% and 45% glycerol and irradiated in electron accelerator type Radiation Dynamics, 0.550 MeV at dose range from 0 to 200 kGy. Thermal properties and mechanical properties were determined using a differential scanning calorimeter and a texture analyzer, respectively. Radiation from electron beam caused a slightly increase on its tensile strength characteristic at 100 kGy, while elongation value at this dose had no reduction

  8. Properties of gelatin-based films incorporated with chitosan-coated microparticles charged with rutin.

    Science.gov (United States)

    Dammak, Ilyes; Bittante, Ana Mônica Quinta Barbosa; Lourenço, Rodrigo Vinicius; do Amaral Sobral, Paulo José

    2017-08-01

    The aim of this study was development an active film based on gelatin incorporated with antioxidant, rutin carried into microparticles. The complexation between oppositely charged lecithin and chitosan was applied to prepare the chitosan-coated microparticles. The generated microparticles had an average size of 520±4nm and a span of 0.3 were formulated by a rotor-stator homogenize at the homogenization speed 10,000rpm. Composite films were prepared by incorporating chitosan-coated microparticles, at various concentrations (0.05, 0.1, 0.5, or 1% (based on the weight of the gelatin powder)) in the gelatin-based films. For the prepared films, the results showed that obtained physicochemical, water vapor barrier, and mechanical were compared with native gelatin film with a slight decrease for chitosan concentration higher than 0.5%. The microstructure studies done by scanning electron microscopes, revealed different micropores embedded with oil resulting from the incorporation of the microparticles into the gelatin matrix. Moreover, the calorimetric results were comparable to those of gelatin control film with T g value 45°C and increased crystallinity percentage with increasing incorporation of microparticles. This original concept of composite biodegradable films may thus be a good alternative to incorporate liposoluble active compounds to design an active packaging with good properties. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Verification of Gamma Knife extend system based fractionated treatment planning using EBT2 film

    Energy Technology Data Exchange (ETDEWEB)

    Natanasabapathi, Gopishankar; Bisht, Raj Kishor [Gamma Knife Unit, Department of Neurosurgery, Neurosciences Centre, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029 (India)

    2013-12-15

    Purpose: This paper presents EBT2 film verification of fractionated treatment planning with the Gamma Knife (GK) extend system, a relocatable frame system for multiple-fraction or serial multiple-session radiosurgery.Methods: A human head shaped phantom simulated the verification process for fractionated Gamma Knife treatment. Phantom preparation for Extend Frame based treatment planning involved creating a dental impression, fitting the phantom to the frame system, and acquiring a stereotactic computed tomography (CT) scan. A CT scan (Siemens, Emotion 6) of the phantom was obtained with following parameters: Tube voltage—110 kV, tube current—280 mA, pixel size—0.5 × 0.5 and 1 mm slice thickness. A treatment plan with two 8 mm collimator shots and three sectors blocking in each shot was made. Dose prescription of 4 Gy at 100% was delivered for the first fraction out of the two fractions planned. Gafchromic EBT2 film (ISP Wayne, NJ) was used as 2D verification dosimeter in this process. Films were cut and placed inside the film insert of the phantom for treatment dose delivery. Meanwhile a set of films from the same batch were exposed from 0 to 12 Gy doses for calibration purposes. An EPSON (Expression 10000 XL) scanner was used for scanning the exposed films in transparency mode. Scanned films were analyzed with inhouse written MATLAB codes.Results: Gamma index analysis of film measurement in comparison with TPS calculated dose resulted in high pass rates >90% for tolerance criteria of 1%/1 mm. The isodose overlay and linear dose profiles of film measured and computed dose distribution on sagittal and coronal plane were in close agreement.Conclusions: Through this study, the authors propose treatment verification QA method for Extend frame based fractionated Gamma Knife radiosurgery using EBT2 film.

  10. Verification of Gamma Knife extend system based fractionated treatment planning using EBT2 film

    International Nuclear Information System (INIS)

    Natanasabapathi, Gopishankar; Bisht, Raj Kishor

    2013-01-01

    Purpose: This paper presents EBT2 film verification of fractionated treatment planning with the Gamma Knife (GK) extend system, a relocatable frame system for multiple-fraction or serial multiple-session radiosurgery.Methods: A human head shaped phantom simulated the verification process for fractionated Gamma Knife treatment. Phantom preparation for Extend Frame based treatment planning involved creating a dental impression, fitting the phantom to the frame system, and acquiring a stereotactic computed tomography (CT) scan. A CT scan (Siemens, Emotion 6) of the phantom was obtained with following parameters: Tube voltage—110 kV, tube current—280 mA, pixel size—0.5 × 0.5 and 1 mm slice thickness. A treatment plan with two 8 mm collimator shots and three sectors blocking in each shot was made. Dose prescription of 4 Gy at 100% was delivered for the first fraction out of the two fractions planned. Gafchromic EBT2 film (ISP Wayne, NJ) was used as 2D verification dosimeter in this process. Films were cut and placed inside the film insert of the phantom for treatment dose delivery. Meanwhile a set of films from the same batch were exposed from 0 to 12 Gy doses for calibration purposes. An EPSON (Expression 10000 XL) scanner was used for scanning the exposed films in transparency mode. Scanned films were analyzed with inhouse written MATLAB codes.Results: Gamma index analysis of film measurement in comparison with TPS calculated dose resulted in high pass rates >90% for tolerance criteria of 1%/1 mm. The isodose overlay and linear dose profiles of film measured and computed dose distribution on sagittal and coronal plane were in close agreement.Conclusions: Through this study, the authors propose treatment verification QA method for Extend frame based fractionated Gamma Knife radiosurgery using EBT2 film

  11. Characterization of edible emulsified films with low affinity to water based on kefiran and oleic acid.

    Science.gov (United States)

    Ghasemlou, Mehran; Khodaiyan, Faramarz; Oromiehie, Abdulrasoul; Yarmand, Mohammad Saeid

    2011-10-01

    New edible composite films based on kefiran and oleic acid (OA) at the ratio of 15, 25, and 35% (w/w) were prepared using emulsification with the aim of improving their water vapour barrier and mechanical properties. Film-forming solutions were characterized in terms of rheological properties and particle-size distribution. The impact of the incorporation of OA into the film matrix was studied by investigating the physical, mechanical, and thermal properties of the films. The water vapour permeability (WVP) of the emulsified films was reduced by approximately 33% by adding OA. The mechanical properties of kefiran films were also affected by adding OA: tensile strength was diminished, and elongation increased considerably. Differential scanning calorimetry showed that the glass transition temperature (T(g)) of the kefiran film was -16°C and was not considerably affected by adding OA. Therefore, OA could be incorporated into these films for some food-technology applications that need a low affinity toward water. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Metallic Langmuir and Langmuir-Blodgett films based on TTF derivatives and fatty acid

    International Nuclear Information System (INIS)

    Ohnuki, H.; Ishizaki, Y.; Suzuki, M.; Desbat, B.; Delhaes, P.; Giffard, M.; Imakubo, T.; Mabon, G.; Izumi, M.

    2002-01-01

    Recent progress in the metallic conducting Langmuir-Blodgett (LB) films built from TTF derivative and fatty acids is reported. A simple LB method of transferring the mixed Langmuir (L) film of BEDO-TTF (BO) and stearic acid (SA) onto substrates provided metallic conducting LB films. A homogeneous L film formation on the water surface observed by Brewster angle microscope (BAM) is an essential factor for the well-ordered LB films. In the L film, the carboxylate group of fatty acid forms anion layer bringing about a spontaneous formation of mixed valence state (MVS) of BO layer. Similar spontaneous formation was also found in the molecular combination of nonoxygen-substituted donor of EDT-TTF and octadecanesulfonic acid (OS). This type of reaction would be useful for obtaining conducting LB films. For the LB films of BEDO-TTF and stearic acid, we found a negative transverse magnetoresistance at low temperature that was interpreted in the weak localization of a two-dimensional (2D) electronic system based on the well-defined conducting layer

  13. Screen printed thick film based pMUT arrays

    DEFF Research Database (Denmark)

    Hedegaard, Tobias; Pedersen, T; Thomsen, Erik Vilain

    2008-01-01

    This article reports on the fabrication and characterization of lambda-pitched piezoelectric micromachined ultrasound transducer (pMUT) arrays fabricated using a unique process combining conventional silicon technology and low cost screen printing of thick film PZT. The pMUTs are designed as 8...

  14. Performance of polymeric films based thermoplastic starch and organophilic clay

    International Nuclear Information System (INIS)

    Cipriano, P.B.; Costa, A.N.M.; Araujo, S.S.; Araujo, A.R.A.; Canedo, E.L.; Carvalho, L.H.

    2010-01-01

    The aim of this work was the development and investigation of the properties of flat films of LDPE/corn thermoplastic starch (TPS). A bentonite clay (Argel) was organophilized and characterized by XRD. This clay (1%) in both pristine and organophilic forms was added to the matrix (LDPE) and to LDPE/TPS systems with TPS contents varying from 5-20% w/w. The films manufactured (LDPE, LDPE/Clay, LDPE/TPS, LDPE/TPS/Clay) were characterized. Results indicate that water vapor permeability is dependent and increases with TPS content which was attributed to the higher affinity of water by TPS. TPS and Clay addition to LDPE led to significant changes in film properties with respect to the neat LDPE. In general,tensile and perforation forces increased with clay and TPS contents; the strength of thermo sealed films lowered with natural clay addition and increased with TPS and organoclay incorporation and, in general, dynamic friction coefficient decrease with organoclay and TPS addition. Best overall properties were obtained for the systems containing the organoclay and optimal properties were achieved for the 5%TPS10 LDPE1% ANO system. (author)

  15. Thin metal films in resistivity-based chemical sensing

    Czech Academy of Sciences Publication Activity Database

    Podešva, Pavel; Foret, František

    2013-01-01

    Roč. 9, č. 4 (2013), s. 642-652 ISSN 1573-4110 R&D Projects: GA ČR(CZ) GAP301/11/2055 Institutional support: RVO:68081715 Keywords : voltohmmetric sensing * chemiresistor * thin metal film * gas sensing Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 1.194, year: 2013

  16. Film-based Sensors with Piezoresistive Molecular Conductors as Active Components Strain Damage and Thermal Regeneration

    Directory of Open Access Journals (Sweden)

    Elena Laukhina

    2011-02-01

    Full Text Available The article is addressed to the development of flexible all-organic bi layer (BL film-based sensors being capable of measuring strain as a well-defined electrical signal in a wide range of elongations and temperature. The purpose was achieved by covering polycarbonate films with the polycrystalline layer of a high piezoresistive organic molecular conductor. To determine restrictions for sensor applications, the effect of monoaxial strain on the resistance and texture of the sensing layers of BL films was studied. The experiments have shown that the maximum strain before fracture is about 1 %. A thermal regeneration of the sensing layer of the BL film-based sensors that were damaged by cyclic load is also described. These sensors are able to take the place of conventional metal-based strain and pressure gages in low cost innovative controlling and monitoring technologies.

  17. Preparation and Characterization of Polyvinyl Alcohol-Chitosan Composite Films Reinforced with Cellulose Nanofiber

    Science.gov (United States)

    Choo, Kaiwen; Ching, Yern Chee; Chuah, Cheng Hock; Julai, Sabariah; Liou, Nai-Shang

    2016-01-01

    In this study microcrystalline cellulose (MCC) was oxidized by 2,2,6,6-tetramethylpiperidine-1-oxyl radical (TEMPO)-mediated oxidation. The treated cellulose slurry was mechanically homogenized to form a transparent dispersion which consisted of individual cellulose nanofibers with uniform widths of 3–4 nm. Bio-nanocomposite films were then prepared from a polyvinyl alcohol (PVA)-chitosan (CS) polymeric blend with different TEMPO-oxidized cellulose nanofiber (TOCN) contents (0, 0.5, 1.0 and 1.5 wt %) via the solution casting method. The characterizations of pure PVA/CS and PVA/CS/TOCN films were performed in terms of field emission scanning electron microscopy (FESEM), tensile tests, thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The results from FESEM analysis justified that low loading levels of TOCNs were dispersed uniformly and homogeneously in the PVA-CS blend matrix. The tensile strength and thermal stability of the films were increased with the increased loading levels of TOCNs to a maximum level. The thermal study indicated a slight improvement of the thermal stability upon the reinforcement of TOCNs. As evidenced by the FTIR and XRD, PVA and CS were considered miscible and compatible owing to hydrogen bonding interaction. These analyses also revealed the good dispersion of TOCNs within the PVA/CS polymer matrix. The improved properties due to the reinforcement of TOCNs can be highly beneficial in numerous applications. PMID:28773763

  18. Characterization of corn starch-based edible film incorporated with nutmeg oil nanoemulsion

    Science.gov (United States)

    Aisyah, Y.; Irwanda, L. P.; Haryani, S.; Safriani, N.

    2018-05-01

    This study aimed to formulate corn starch-based edible films by varying concentrations of nutmeg oil nanoemulsion and glycerol. Furthermore, the resulted edible film was characterized by its mechanical properties and antibacterial activity. The edible films were made using corn starch, nutmeg oil nanoemulsion, and glycerol. Concentrations of nutmeg oil nanoemulsion were 1%, 2%, and 3%, and glycerol were 10%, 20%, and 30%. Results indicated that the increase of nutmeg oil nanoemulsion concentration could increase the film thickness. However, the nutmeg oil had no effect on the film tensile strength and elongation. Glycerol had no effect on the film tensile strength. The best treatment of the corn starch-based film was obtained by adding 1% of nutmeg oil and 30% of glycerol, yielding a tensile strength of 18.73 Kgf/mm2, elongation of 69.44% and thickness of 0.0840. The addition of 1% nutmeg oil nanoemulsion has been able to inhibit the growth of two types of the bacteria tested (Staphylococcus aureus and Escherichia coli).

  19. Zein-based films and their usage for controlled delivery: Origin, classes and current landscape.

    Science.gov (United States)

    Zhang, Yong; Cui, Lili; Che, Xiaoxia; Zhang, Heng; Shi, Nianqiu; Li, Chunlei; Chen, Yan; Kong, Wei

    2015-05-28

    Zein is a class of alcohol-soluble prolamine proteins present in maize endosperm, which was approved as a generally recognized as safe (GRAS) excipient in 1985 by the United States Food and Drug Administration (US-FDA) for film coating of pharmaceuticals, e.g., tablets. Despite its long-term application in tablet production, effects of zein coating on tablet properties are still not fully understood. Moreover, many studies have also been conducted to illustrate its potential as an active ingredient of direct compressed tablets and film-based delivery carriers. In addition, the use of zein as a functional film coating material for new biomedical applications was also widely investigated in recent reports, which involved medical devices, nanoparticles, quantum dots and nanofibers. In this review, the present status of zein in the form of a thin film and uniform layer for use as a biomedical material is discussed. In addition, studies related to the behaviors and properties of zein films are also summarized and analyzed based on published works to gain mechanistic insights into the relationship between zein film and various improved profiles. This review will benefit future prospects of the use of zein film in drug delivery and biomedical applications. Copyright © 2015 Elsevier B.V. All rights reserved.

  20. Electroplated Fe-Co-Ni films prepared from deep-eutectic-solvent-based plating baths

    Directory of Open Access Journals (Sweden)

    Takeshi Yanai

    2016-05-01

    Full Text Available We fabricated soft magnetic films from DES-based plating baths, and investigated magnetic properties of the plated films. The plating baths were obtained by stirring the mixture of choline chloride, ethylene glycol, FeCl2 ⋅ 4H2O, NiCl2 ⋅ 6H2O and CoCl2 ⋅ 6H2O. The composition of the electroplated film depended on the amount of the reagent in the plating bath, and we consequently obtained the films with various composition. The current efficiency of the plating process shows high values (> 88 % in the wide composition range. The soft magnetic films with low coercivity were obtained at the Fe compositions of ≈ 30 at.% and > 80 at.%, and we found that low coercivity could be realized by the control of the film composition. We also found that the Fe-rich films prepared from DES-based plating bath have some advantages as a soft magnetic phase for a nanocomposite magnet due to their high saturation magnetization and very fine crystal structure.

  1. Sensitive Capacitive-type Hydrogen Sensor Based on Ni Thin Film in Different Hydrogen Concentrations.

    Science.gov (United States)

    Pour, Ghobad Behzadi; Aval, Leila Fekri; Eslami, Shahnaz

    2018-04-01

    Hydrogen sensors are micro/nano-structure that are used to locate hydrogen leaks. They are considered to have fast response/recovery time and long lifetime as compared to conventional gas sensors. In this paper, fabrication of sensitive capacitive-type hydrogen gas sensor based on Ni thin film has been investigated. The C-V curves of the sensor in different hydrogen concentrations have been reported. Dry oxidation was done in thermal chemical vapor deposition furnace (TCVD). For oxidation time of 5 min, the oxide thickness was 15 nm and for oxidation time 10 min, it was 20 nm. The Ni thin film as a catalytic metal was deposited on the oxide film using electron gun deposition. Two MOS sensors were compared with different oxide film thickness and different hydrogen concentrations. The highest response of the two MOS sensors with 15 nm and 20 nm oxide film thickness in 4% hydrogen concentration was 87.5% and 65.4% respectively. The fast response times for MOS sensors with 15 nm and 20 nm oxide film thickness in 4% hydrogen concentration was 8 s and 21 s, respectively. By increasing the hydrogen concentration from 1% to 4%, the response time for MOS sensor (20nm oxide thickness), was decreased from 28s to 21s. The recovery time was inversely increased from 237s to 360s. The experimental results showed that the MOS sensor based on Ni thin film had a quick response and a high sensitivity.

  2. Evaluation of a LED-based flatbed document scanner for radiochromic film dosimetry in transmission mode.

    Science.gov (United States)

    Lárraga-Gutiérrez, José Manuel; García-Garduño, Olivia Amanda; Treviño-Palacios, Carlos; Herrera-González, José Alfredo

    2018-03-01

    Flatbed scanners are the most frequently used reading instrument for radiochromic film dosimetry because its low cost, high spatial resolution, among other advantages. These scanners use a fluorescent lamp and a CCD array as light source and detector, respectively. Recently, manufacturers of flatbed scanners replaced the fluorescent lamp by light emission diodes (LED) as a light source. The goal of this work is to evaluate the performance of a commercial flatbed scanner with LED based source light for radiochromic film dosimetry. Film read out consistency, response uniformity, film-scanner sensitivity, long term stability and total dose uncertainty was evaluated. In overall, the performance of the LED flatbed scanner is comparable to that of a cold cathode fluorescent lamp (CCFL). There are important spectral differences between LED and CCFL lamps that results in a higher sensitivity of the LED scanner in the green channel. Total dose uncertainty, film response reproducibility and long-term stability of LED scanner are slightly better than those of the CCFL. However, the LED based scanner has a strong non-uniform response, up to 9%, that must be adequately corrected for radiotherapy dosimetry QA. The differences in light emission spectra between LED and CCFL lamps and its potential impact on film-scanner sensitivity suggest that the design of a dedicated flat-bed scanner with LEDs may improve sensitivity and dose uncertainty in radiochromic film dosimetry. Copyright © 2018 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  3. High melt strength, tear resistant blown film based on poly(lactic acid)

    Science.gov (United States)

    Edmonds, Neil R.; Plimmer, Peter N.; Tanner, Chris

    2015-05-01

    A major problem associated with the commercial manufacture of thin films from PLA is inferior processing characteristics on blown film lines compared to low density polyethylene. PLA has poor melt strength (leading to bubble instability) and develops a permanent crease in the flattened film as it exits the tower of the film line. In addition, the thin film product has poor tear strength and an unacceptable `noise' level when converted into flexible packaging. Furthermore, fabricated articles based on PLA are known to show an unattractive tendency toward dimensional instability. This behaviour is associated with `cold crystallization', a phenomenon which also causes exudation of any plasticizer added for improving flexibility. Blow moulded articles based on PLA also exhibit dimensional sensitivity above 60°C. All of these issues have been overcome by the technology described in this paper. This has been accomplished without loss of the valuable compostability characteristic of PLA; this was confirmed by evaluation of film in a commercial composting operation. These results have been achieved through novel reactive compounding technology which: (a) Creates a PLA-rich structure containing long chain crosslinks, (b) generates a low glass transition temperature phase covalently bonded to the PLA structure, and (c) provides a material which performs like LDPE in a blown film manufacturing operation. The technology developed is covered by NZ Patent 580231 (3). The patent is held by UniServices Ltd, The University of Auckland, New Zealand.

  4. Ratiometric glucose sensing based on fluorescent oxygen films and glucose oxidase

    OpenAIRE

    Fengyu Su; Liqiang Zhang; Xiangxing Kong; Fred Lee; Yanqing Tian; Deirdre R. Meldrum

    2017-01-01

    A new two-layer sensor film was constructed for sensing glucose based on glucose oxidase and oxygen sensing material. The first layer of film containing the oxygen sensor and intra-reference material was polymerized, then the second layer of glucose oxidase and glutaraldehyde was formed on the oxygen sensor layer. The two-layer sensor film has a resolution up to 0.05 mM and a detection range from 0 to 5 mM to glucose. The effects of pH and temperature on the sensing performance were systemati...

  5. Tiny optical fiber temperature sensor based on temperature-dependent refractive index of zinc telluride film

    Science.gov (United States)

    Bian, Qiang; Song, Zhangqi; Song, Dongyu; Zhang, Xueliang; Li, Bingsheng; Yu, Yang; Chen, Yuzhong

    2018-03-01

    The temperature-dependent refractive index of zinc telluride film can be used to develop a tiny, low cost and film-coated optical fiber temperature sensor. Pulse reference-based compensation technique is used to largely reduce the background noise which makes it possible to detect the minor reflectivity change of the film in different temperatures. The temperature sensitivity is 0.0034dB/° and the background noise is measured to be 0.0005dB, so the resolution can achieve 0.2°.

  6. Positron and positronium annihilation in silica-based thin films studied by a pulsed positron beam

    International Nuclear Information System (INIS)

    Suzuki, R.; Ohdaira, T.; Kobayashi, Y.; Ito, K.; Shioya, Y.; Ishimaru, T.

    2003-01-01

    Positron and positronium annihilation in silica-based thin films has been investigated by means of measurement techniques with a monoenergetic pulsed positron beam. The age-momentum correlation study revealed that positron annihilation in thermally grown SiO 2 is basically the same as that in bulk amorphous SiO 2 while o-Ps in the PECVD grown SiCOH film predominantly annihilate with electrons of C and H at the microvoid surfaces. We also discuss time-dependent three-gamma annihilation in porous low-k films by two-dimensional positron annihilation lifetime spectroscopy

  7. AlScN thin film based surface acoustic wave devices with enhanced microfluidic performance

    OpenAIRE

    Wang, Wenbo; Fu, Yong Qing; Chen, Jinju; Xuan, Weipeng; Chen, Jinkai; Mayrhofer, Paul; Duan, Pengfei; Bittner, Elmar; Luo, Jikui

    2016-01-01

    This paper reports the characterization of scandium aluminum nitride (Al1−x Sc x N, x  =  27%) films and discusses surface acoustic wave (SAW) devices based on them. Both AlScN and AlN films were deposited on silicon by sputtering and possessed columnar microstructures with (0 0 0 2) crystal orientation. The AlScN/Si SAW devices showed improved electromechanical coupling coefficients (K 2, ~2%) compared with pure AlN films (

  8. Brain-based decoding of mentally imagined film clips and sounds reveals experience-based information patterns in film professionals.

    Science.gov (United States)

    de Borst, Aline W; Valente, Giancarlo; Jääskeläinen, Iiro P; Tikka, Pia

    2016-04-01

    In the perceptual domain, it has been shown that the human brain is strongly shaped through experience, leading to expertise in highly-skilled professionals. What has remained unclear is whether specialization also shapes brain networks underlying mental imagery. In our fMRI study, we aimed to uncover modality-specific mental imagery specialization of film experts. Using multi-voxel pattern analysis we decoded from brain activity of professional cinematographers and sound designers whether they were imagining sounds or images of particular film clips. In each expert group distinct multi-voxel patterns, specific for the modality of their expertise, were found during classification of imagery modality. These patterns were mainly localized in the occipito-temporal and parietal cortex for cinematographers and in the auditory cortex for sound designers. We also found generalized patterns across perception and imagery that were distinct for the two expert groups: they involved frontal cortex for the cinematographers and temporal cortex for the sound designers. Notably, the mental representations of film clips and sounds of cinematographers contained information that went beyond modality-specificity. We were able to successfully decode the implicit presence of film genre from brain activity during mental imagery in cinematographers. The results extend existing neuroimaging literature on expertise into the domain of mental imagery and show that experience in visual versus auditory imagery can alter the representation of information in modality-specific association cortices. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Synchronous determination of mercury (II) and copper (II) based on quantum dots-multilayer film

    International Nuclear Information System (INIS)

    Ma Qiang; Ha Enna; Yang Fengping; Su Xingguang

    2011-01-01

    Graphical abstract: We developed a sensitive sensor for synchronous detection of Hg (II) and Cu (II) based on the quenchedand recovered PL intensity of QDs-multilayer films. Solutions containing Hg (II) or Cu (II) were used to quench the fluorescence of the QDs-multilayer films firstly. Then, glutathione (GSH) was used to remove Hg (II) or Cu (II) from the QDs-multilayer films due to stronger affinity of GSH-metal ions than that of QDs metal ions. Thus, the fluorescence of QDs-multilayer films was recovered. Highlights: → QDs-multilayer films were developed for synchronous detection of Hg (II) and Cu (II). → Hg (II) and Cu (II) could quench the photoluminescence of the QDs-multilayer films. → Glutathione was used to remove metal ions and recovery photoluminescence of QDs-multilayer films. - Abstract: A sensitive sensor for mercury (II) and copper (II) synchronous detection was established via the changed photoluminescence of CdTe quantum dots (QDs) multilayer films in this work. QDs were deposited on the quartz slides to form QDs-multilayer films by electrostatic interactions with poly(dimethyldiallyl ammonium chloride) (PDDA). Hg 2+ or Cu 2+ could quench the photoluminescence of the QDs-multilayer films, and glutathione (GSH) was used to remove Hg 2+ or Cu 2+ from QDs-multilayer films due to strong affinity of GSH-metal ions, which resulted in the recovered photoluminescence of QDs-multilayer films. There are good linear relationships between the metal ions concentration and the photoluminescence intensity of QDs in the quenched and recovered process. It was found that the Stern-Volmer constants for Hg 2+ are higher than that for Cu 2+ . Based on different quenching and recovery constant between Hg 2+ and Cu 2+ , the synchronous detection of Hg 2+ and Cu 2+ can be achieved. The linear ranges of this assay were obtained from 0.005 to 0.5 μM for Hg 2+ and from 0.01 to 1 μM for Cu 2+ , respectively. And the artificial water samples were determined by this

  10. Ultrathin monomolecular films and robust assemblies based on cyclic catechols

    Czech Academy of Sciences Publication Activity Database

    Zieger, M. M.; Pop-Georgievski, Ognen; de los Santos Pereira, Andres; Verveniotis, E.; Preuss, C. M.; Zorn, M.; Reck, B.; Goldmann, A. S.; Rodriguez-Emmenegger, Cesar; Barner-Kowollik, C.

    2017-01-01

    Roč. 33, č. 3 (2017), s. 670-679 ISSN 0743-7463 R&D Projects: GA ČR(CZ) GJ15-09368Y Grant - others:OPPK(XE) CZ.2.16/3.1.00/21545 Program:OPPK Institutional support: RVO:61389013 Keywords : cyclic catechols * ultrathin films * macromolecules monolayers Subject RIV: CD - Macromolecular Chemistry OBOR OECD: Polymer science Impact factor: 3.833, year: 2016

  11. Photoluminescence-based quality control for thin film absorber layers of photovoltaic devices

    Science.gov (United States)

    Repins, Ingrid L.; Kuciauskas, Darius

    2015-07-07

    A time-resolved photoluminescence-based system providing quality control during manufacture of thin film absorber layers for photovoltaic devices. The system includes a laser generating excitation beams and an optical fiber with an end used both for directing each excitation beam onto a thin film absorber layer and for collecting photoluminescence from the absorber layer. The system includes a processor determining a quality control parameter such as minority carrier lifetime of the thin film absorber layer based on the collected photoluminescence. In some implementations, the laser is a low power, pulsed diode laser having photon energy at least great enough to excite electron hole pairs in the thin film absorber layer. The scattered light may be filterable from the collected photoluminescence, and the system may include a dichroic beam splitter and a filter that transmit the photoluminescence and remove scattered laser light prior to delivery to a photodetector and a digital oscilloscope.

  12. A comparative study of oxygen transmission rates through polymer films based on fluorescence quenching

    DEFF Research Database (Denmark)

    Siró, Istvan; Plackett, David; Sommer-Larsen, Peter

    2010-01-01

    Information on oxygen permeability through polymer films is essential for some applications, especially in food packaging where the control of oxygen levels can be critical in avoiding food spoilage. A permeability testing device using fluorescence-based optical oxygen sensing was developed...... as a potential new instrument for measuring the oxygen permeability of packaging films. The fluorescence-based permeability tester was validated against two existing commercial oxygen permeability measuring devices, the Mocon Ox-Tran 2/20 and PBI-Dansensor OPT-5000. Oxygen transmission rates (OTR) of polylactide...... (PLA) and nanoclay-reinforced PLA films, as well as polyethylene/poly(ethylene terephthalate) (PE/PET) and polypropylene/poly(ethylene terephthalate) (PP/PET) laminated films were determined at 23°C and 50% relative humidity using each of these instruments. No significant differences were observed...

  13. Wearable strain sensors based on thin graphite films for human activity monitoring

    Science.gov (United States)

    Saito, Takanari; Kihara, Yusuke; Shirakashi, Jun-ichi

    2017-12-01

    Wearable health-monitoring devices have attracted increasing attention in disease diagnosis and health assessment. In many cases, such devices have been prepared by complicated multistep procedures which result in the waste of materials and require expensive facilities. In this study, we focused on pyrolytic graphite sheet (PGS), which is a low-cost, simple, and flexible material, used as wearable devices for monitoring human activity. We investigated wearable devices based on PGSs for the observation of elbow and finger motions. The thin graphite films were fabricated by cutting small films from PGSs. The wearable devices were then made from the thin graphite films assembled on a commercially available rubber glove. The human motions could be observed using the wearable devices. Therefore, these results suggested that the wearable devices based on thin graphite films may broaden their application in cost-effective wearable electronics for the observation of human activity.

  14. Oxygen reduction activity of N-doped carbon-based films prepared by pulsed laser deposition

    Science.gov (United States)

    Hakoda, Teruyuki; Yamamoto, Shunya; Kawaguchi, Kazuhiro; Yamaki, Tetsuya; Kobayashi, Tomohiro; Yoshikawa, Masahito

    2010-12-01

    Carbon-based films with nitrogen species on their surface were prepared on a glassy carbon (GC) substrate for application as a non-platinum cathode catalyst for polymer electrolyte fuel cells. Cobalt and carbon were deposited in the presence of N 2 gas using a pulsed laser deposition method and then the metal Co was removed by HCl-washing treatment. Oxygen reduction reaction (ORR) activity was electrochemically determined using a rotating disk electrode system in which the film samples on the GC substrate were replaceable. The ORR activity increased with the temperature of the GC substrate during deposition. A carbon-based film prepared at 600 °C in the presence of N 2 at 66.7 Pa showed the highest ORR activity among the tested samples (0.66 V vs. NHE). This film was composed of amorphous carbons doped with pyridine type nitrogen atoms on its surface.

  15. Cycle water chemistry based on film forming amines at power plants: evaluation of technical guidance documents

    Science.gov (United States)

    Dyachenko, F. V.; Petrova, T. I.

    2017-11-01

    Efficiency and reliability of the equipment in fossil power plants as well as in combined cycle power plants depend on the corrosion processes and deposit formation in steam/water circuit. In order to decrease these processes different water chemistries are used. Today the great attention is being attracted to the application of film forming amines and film forming amine products. The International Association for the Properties of Water and Steam (IAPWS) consolidated the information from all over the World, and based on the research studies and operating experience of researchers and engineers from 21 countries, developed and authorized the Technical Guidance Document: “Application of Film Forming Amines in Fossil, Combined Cycle, and Biomass Power Plants” in 2016. This article describe Russian and International technical guidance documents for the cycle water chemistries based on film forming amines at fossil and combined cycle power plants.

  16. Understanding the distribution of natural wax in starch-wax films using synchrotron-based FTIR (S-FTIR).

    Science.gov (United States)

    Muscat, Delina; Tobin, Mark J; Guo, Qipeng; Adhikari, Benu

    2014-02-15

    High amylose starch-glycerol (HAG) films were produced incorporating beeswax, candelilla wax and carnauba wax in the presence and absence of Tween-80 in order to determine the distribution of wax in the films during the film formation process. The distribution of these waxes within the film was studied using Synchrotron based Fourier Transform Infrared Spectroscopy (S-FTIR) which provided 2D mapping along the thickness of the film. The incorporation of 5% and 10% wax in HAG films produced randomly distributed wax or wax-rich domains, respectively, within these films. Consequently, the addition of these waxes to HAG increased the surface roughness and hydrophobicity of these films. The addition of Tween-80 caused variations in wax-rich bands within the films. The HAG+carnauba wax+Tween-80 films exhibited domed wax-rich domains displayed with high integrated CH2 absorption value at the interior of the films, rougher surface and higher contact angle values than the other films. The S-FTIR 2D images indicated that the distribution of wax in starch-wax films correlated with the roughness and hydrophobicity of the starch-wax films. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Flexible Transparent Supercapacitors Based on Hierarchical Nanocomposite Films.

    Science.gov (United States)

    Chen, Fanhong; Wan, Pengbo; Xu, Haijun; Sun, Xiaoming

    2017-05-31

    Flexible transparent electronic devices have recently gained immense popularity in smart wearable electronics and touch screen devices, which accelerates the development of the portable power sources with reliable flexibility, robust transparency and integration to couple these electronic devices. For potentially coupled as energy storage modules in various flexible, transparent and portable electronics, the flexible transparent supercapacitors are developed and assembled from hierarchical nanocomposite films of reduced graphene oxide (rGO) and aligned polyaniline (PANI) nanoarrays upon their synergistic advantages. The nanocomposite films are fabricated from in situ PANI nanoarrays preparation in a blended solution of aniline monomers and rGO onto the flexible, transparent, and stably conducting film (FTCF) substrate, which is obtained by coating silver nanowires (Ag NWs) layer with Meyer rod and then coating of rGO layer on polyethylene terephthalate (PET) substrate. Optimization of the transparency, the specific capacitance, and the flexibility resulted in the obtained all-solid state nanocomposite supercapacitors exhibiting enhanced capacitance performance, good cycling stability, excellent flexibility, and superior transparency. It provides promising application prospects for exploiting flexible, low-cost, transparent, and high-performance energy storage devices to be coupled into various flexible, transparent, and wearable electronic devices.

  18. II-IV-V Based Thin Film Tandem Photovoltaic Cell

    Energy Technology Data Exchange (ETDEWEB)

    Newman, Nathan [Arizona State Univ., Mesa, AZ (United States); van Schilfgaarde, Mark [Arizona State Univ., Mesa, AZ (United States)

    2012-10-04

    [Through a combination of theory and experiment that, absent unknown mitigating factors, a tandem cell whose (wide-gap. 1.8 eV) top layer is made of ZnSnP2 and whose (narrow gap, 1.1 eV) bottom layer consisting of ZnGeAs2 are near-ideal materials for a tandem cell. Not only are there gaps optimally adjusted to the solar spectrum, but the two compounds are lattice-matched, and their energy band structure and optical absorption are also near-ideal (they closely resemble that of GaAs). Our first major challenge is to establish that high-quality II-IV-V thin films can be synthesized. We have begun growing and characterizing films of ZnGeAs2 and ZnSnP2, initially grown on Ge substrates (the lattice constant of Ge matches these compounds) by pulsed laser ablation and sputtering. In tandem are theoretical calculations to guide the experiments. The goal is to develop methods that can be used to produce a pair of lattice-matched thin films that will be useful in tandem cells.

  19. Nanocomposites Based on Polyethylene and Nanocrystalline Silicon Films

    Directory of Open Access Journals (Sweden)

    Olkhov Anatoliy Aleksandrovich

    2014-12-01

    Full Text Available High-strength polyethylene films containing 0.5-1.0 wt. % of nanocrystalline silicon (nc-Si were synthesized. Samples of nc-Si with an average core diameter of 7-10 nm were produced by plasmochemical method and by laser-induced decomposition of monosilane. Spectral studies revealed almost complete (up to ~95 % absorption of UV radiation in 200- 400 nm spectral region by 85 micron thick film if the nc-Si content approaches to 1.0 wt. %. The density function of particle size in the starting powders and polymer films containing immobilized silicon nanocrystallites were obtained using the modeling a complete profile of X-ray diffraction patterns, assuming spherical grains and the lognormal distribution. The results of X-ray analysis shown that the crystallite size distribution function remains almost unchanged and the crystallinity of the original polymer increases to about 10 % with the implantation of the initial nc-Si samples in the polymer matrix.

  20. ZnO based transparent conductive oxide films with controlled type of conduction

    Energy Technology Data Exchange (ETDEWEB)

    Zaharescu, M., E-mail: mzaharescu@icf.ro [Institute of Physical Chemistry “Ilie Murgulescu”, Romanian Academy, 202 Splaiul Independentei, 060021 Bucharest (Romania); Mihaiu, S., E-mail: smihaiu@icf.ro [Institute of Physical Chemistry “Ilie Murgulescu”, Romanian Academy, 202 Splaiul Independentei, 060021 Bucharest (Romania); Toader, A. [Institute of Physical Chemistry “Ilie Murgulescu”, Romanian Academy, 202 Splaiul Independentei, 060021 Bucharest (Romania); Atkinson, I., E-mail: irinaatkinson@yahoo.com [Institute of Physical Chemistry “Ilie Murgulescu”, Romanian Academy, 202 Splaiul Independentei, 060021 Bucharest (Romania); Calderon-Moreno, J.; Anastasescu, M.; Nicolescu, M.; Duta, M.; Gartner, M. [Institute of Physical Chemistry “Ilie Murgulescu”, Romanian Academy, 202 Splaiul Independentei, 060021 Bucharest (Romania); Vojisavljevic, K.; Malic, B. [Institute Jožef Stefan, Ljubljana (Slovenia); Ivanov, V.A.; Zaretskaya, E.P. [State Scientific and Production Association “Scientific-Practical Materials Research Center of the National Academy of Science Belarus, P. Brovska str.19, 220072, Minsk (Belarus)

    2014-11-28

    The transparent conductive oxide films with controlled type of conduction are of great importance and their preparation is intensively studied. In our work, the preparation of such films based on doped ZnO was realized in order to achieve controlled type of conduction and high concentration of the charge carriers. Sol–gel method was used for films preparation and several dopants were tested (Sn, Li, Ni). Multilayer deposition was performed on several substrates: SiO{sub 2}/Si wafers, silica-soda-lime and/or silica glasses. The structural and morphological characterization of the obtained films were done by scanning electron microscopy, X-ray diffraction, X-ray fluorescence, X-ray photoelectron spectroscopy and atomic force microscopy respectively, while spectroscopic ellipsometry and transmittance measurements were done for determination of optical properties. The selected samples with the best structural, morphological and optical properties were subjected to electrical measurement (Hall and Seebeck effect). In all studied cases, samples with good adherence and homogeneous morphology as well as monophasic wurtzite type structure were obtained. The optical constants (refractive index and extinction coefficient) were calculated from spectroscopic ellipsometry data using Cauchy model. Films with n- or p-type conduction were obtained depending on the composition, number of deposition and thermal treatment temperature. - Highlights: • Transparent conductive ZnO based thin films were prepared by the sol–gel method. • Controlled type of conduction is obtained in (Sn, Li) doped and Li-Ni co-doped ZnO films. • Hall and Seebeck measurements proved the p-type conductivity for Li-Ni co-doped ZnO films. • The p-type conductivity was maintained even after 4-months of storage. • Influence of dopant- and substrate-type on the ZnO films properties was established.

  1. First-principles-based study of transport properties of Fe thin films on Cu surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Kishi, Tomoya [Department of Applied Physics, Osaka University, Suita, Osaka 565-0871 (Japan); Kasai, Hideaki [Department of Applied Physics, Osaka University, Suita, Osaka 565-0871 (Japan); Nakanishi, Hiroshi [Department of Applied Physics, Osaka University, Suita, Osaka 565-0871 (Japan); Dino, Wilson Agerico [Department of Applied Physics, Osaka University, Suita, Osaka 565-0871 (Japan); Komori, Fumio [Institute for Solid State Physics, University of Tokyo, Kashiwa, Chiba 277-8587 (Japan)

    2004-12-08

    We investigate the transport properties of Fe thin films on Cu(111) based on first principles calculation. We calculate the electron current through these Fe thin films, which can be observed by using a double-tipped scanning tunnelling microscope. We find that the conductance is majority spin polarized. On the basis of the band structures for this system, we discuss the origin of these interesting transport properties.

  2. First-principles-based study of transport properties of Fe thin films on Cu surfaces

    International Nuclear Information System (INIS)

    Kishi, Tomoya; Kasai, Hideaki; Nakanishi, Hiroshi; Dino, Wilson Agerico; Komori, Fumio

    2004-01-01

    We investigate the transport properties of Fe thin films on Cu(111) based on first principles calculation. We calculate the electron current through these Fe thin films, which can be observed by using a double-tipped scanning tunnelling microscope. We find that the conductance is majority spin polarized. On the basis of the band structures for this system, we discuss the origin of these interesting transport properties

  3. Structure and properties of porous films based on aliphatic copolyamide developed for cellular technologies

    Czech Academy of Sciences Publication Activity Database

    Dobrovol`skaya, I.P.; Popryadukhin, P.V.; Yudin, V. E.; Ivankova, E.M.; Elokhovskiy, V.Y.; Weishauptová, Zuzana; Balík, Karel

    2015-01-01

    Roč. 26, č. 1 (2015), article number 46 ISSN 0957-4530 Institutional support: RVO:67985891 Keywords : porous film * aliphatic copolyamide * structure * properties Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.272, year: 2015 http://www.stem-art.com/Library/Science/Structure%20and%20properties%20of%20porous%20films%20based%20on%20aliphatic%20copolyamide%20developed%20for%20cellular%20technologies.pdf

  4. THE USE OF FILM-BASED MATERIAL FOR AN ADULT ENGLISH LANGUAGE COURSE IN BRAZIL

    OpenAIRE

    Parisi,Leonardo Lucena; Andon,Nick

    2016-01-01

    ABSTRACT Advances in technology and accessibility to films motivated the research and writing of this paper. Its main goal was to design a set of criteria to develop film-based materials that can be used to improve the experience of learning English on an adult conversation course in Brazil. Given that the purpose of this adult course is to enhance participants' speaking skills, an investigation was conducted into the theories related to the teaching of speaking. A literature review suggests ...

  5. Study of oxygen scavenging PET-based films activated by water

    Energy Technology Data Exchange (ETDEWEB)

    Rossi, Gabriella; Scarfato, Paola; Incarnato, Loredana [Department of Industrial Engineering, University of Salerno Via Giovanni Paolo II, 132 - 84084 Fisciano (Italy)

    2016-05-18

    In this work an active barrier system consisting of a thin and transparent film based on polyethylene terephthalate (PET) was studied. Dynamic oxygen absorption measurements were performed at different values of relative humidity and temperature, pointing out that humidity is a key factor in activating the oxidation of the polymer sample. Moreover, the thermal and optical properties of the films were investigated and a good correlation was found between the crystallinity increase and the consequent transparency reduction occurring after the oxygen absorption.

  6. Study of oxygen scavenging PET-based films activated by water

    Science.gov (United States)

    Rossi, Gabriella; Scarfato, Paola; Incarnato, Loredana

    2016-05-01

    In this work an active barrier system consisting of a thin and transparent film based on polyethylene terephthalate (PET) was studied. Dynamic oxygen absorption measurements were performed at different values of relative humidity and temperature, pointing out that humidity is a key factor in activating the oxidation of the polymer sample. Moreover, the thermal and optical properties of the films were investigated and a good correlation was found between the crystallinity increase and the consequent transparency reduction occurring after the oxygen absorption.

  7. Synthesis of bio-based nanocomposites for controlled release of antimicrobial agents in food packaging

    Science.gov (United States)

    DeGruson, Min Liu

    The utilization of bio-based polymers as packaging materials has attracted great attention in both scientific and industrial areas due to the non-renewable and nondegradable nature of synthetic plastic packaging. Polyhydroxyalkanoate (PHA) is a biobased polymer with excellent film-forming and coating properties, but exhibits brittleness, insufficient gas barrier properties, and poor thermal stability. The overall goal of the project was to develop the polyhydroxyalkanoate-based bio-nanocomposite films modified by antimicrobial agents with improved mechanical and gas barrier properties, along with a controlled release rate of antimicrobial agents for the inhibition of foodborne pathogens and fungi in food. The ability for antimicrobial agents to intercalate into layered double hydroxides depended on the nature of the antimicrobial agents, such as size, spatial structure, and polarity, etc. Benzoate and gallate anions were successfully intercalated into LDH in the present study and different amounts of benzoate anion were loaded into LDH under different reaction conditions. Incorporation of nanoparticles showed no significant effect on mechanical properties of polyhydroxybutyrate (PHB) films, however, significantly increased the tensile strength and elongation at break of polyhydroxybutyrate-co-valerate (PHBV) films. The effects of type and concentration of LDH nanoparticles (unmodified LDH and LDH modified by sodium benzoate and sodium gallate) on structure and properties of PHBV films were then studied. The arrangement of LDH in the bio-nanocomposite matrices ranged from exfoliated to phase-separated depending on the type and concentration of LDH nanoparticles. Intercalated or partially exfoliated structures were obtained using modified LDH, however, only phase-separated structures were formed using unmodified LDH. The mechanical (tensile strength and elongation at break) and thermo-mechanical (storage modulus) properties were significantly improved with low

  8. Characterization of the Diamond-like Carbon Based Functionally Gradient Film

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Diamond-like carbon coatings have been used as solid lubricating coatings in vacuum technology for their goodphysical and chemical properties. In this paper, the hybrid technique of unbalanced magnetron sputtering and plasmaimmersion ion implantation (PIll) was adopted to fabricate diamond-like carbon-based functionally gradient film,N/TiN/Ti(N,C)/DLC, on the 304 stainless steel substrate. The film was characterized by using Raman spectroscopyand glancing X-ray diffraction (GXRD), and the topography and surface roughness of the film was observed usingAFM. The mechanical properties of the film were evaluated by nano-indentation. The results showed that the surfaceroughness of the film was approximately 0.732 nm. The hardness and elastic modulus, fracture toughness andinterfacial fracture toughness of N/TiN/Ti(N,C)/DLC functionally gradient film were about 19.84 GPa, 190.03 GPa,3.75 MPa.m1/2 and 5.68 MPa@m1/2, respectively. Compared with that of DLC monolayer and C/TiC/DLC multilayer,this DLC gradient film has better qualities as a solid lubricating coating.

  9. Transparent Electrode Based on Silver Nanowires and Polyimide for Film Heater and Flexible Solar Cell.

    Science.gov (United States)

    He, Xin; Duan, Feng; Liu, Junyan; Lan, Qiuming; Wu, Jianhao; Yang, Chengyan; Yang, Weijia; Zeng, Qingguang; Wang, Huafang

    2017-11-29

    Transparent, conductive, and flexible Ag nanowire (NW)-polyimide (PI) composite films were fabricated by a facile solution method. Well-dispersed Ag NWs result in percolation networks on the PI supporting layer. A series of films with transmittance values of 53-80% and sheet resistances of 2.8-16.5 Ω/sq were investigated. To further verify the practicability of the Ag NWs-PI film in optoelectronic devices, we utilized it in a film heater and a flexible solar cell. The film heater was able to generate a temperature of 58 °C at a driving voltage of 3.5 V within 20 s, indicating its potential application in heating devices that require low power consumption and fast response. The flexible solar cell based on the composite film with a transmittance value of 71% presented a power conversion efficiency of 3.53%. These successful applications proved that the fabricated Ag NWs-PI composite film is a good candidate for application in flexible optoelectronic devices.

  10. Effect of acid and alkaline solubilization on the properties of surimi based film

    Directory of Open Access Journals (Sweden)

    Thummanoon Prodpran

    2005-05-01

    Full Text Available The effect of acid and alkaline solubilizing processes on the properties of the protein based film from threadfin bream surimi was investigated. Surimi films prepared from both processes had the similar light transmission, tensile strength (TS and elongation at break (EAB (P<0.05. However, film with alkaline process had slightly lower water vapor permeability (WVP, compared to that prepared by acid solubilizing process. The protein concentration in the film-forming solution directly affected the properties of the film. Increase in protein concentration resulted in an increase in TS, EAB as well as WVP. The film prepared by acid solubilizing process had an increase in yellowish color as evidenced by the continuous increase in b* and E* values during the storage at r oom temperature. The acid and alkali solubilizing processes caused the degradation of muscle protein in surimi, especially with increasing exposure time. Therefore, solubilizing process had the influence on the properties of the protein film from threadfin bream surimi.

  11. Formation of sterilized edible-films based on caseinates: Effects of calcium and plasticizers

    International Nuclear Information System (INIS)

    Mezgheni, E.; D'Aprano, G.; Lacroix, M.

    1998-01-01

    Gamma-irradiation was used to produce free-standing sterilized edible films based on caseinate. The effect of calcium ions (Ca 2+ ) and two plasticizers, namely propylene glycol (PG) and triethylene glycol (TEG) were investigated, as well as the effect of the irradiation on both the gel formation and mechanical properties of the resulting films. Gamma-irradiation provoked formation of bityrosine, i.e. crosslinks, accounting for the increase of the puncture strength of films. The presence of PG or TEG enhanced the formation of crosslinks, leading to an improved mechanical strength of films. TEG was found to interact more favorably with the caseinate than PG, being responsible for the improved film extensibility. Addition of CA 2+ caused the formation of gels. The breaking strength of gels was directly related to the concentration of Ca 2+ , while the puncture strength of films was found to be almost independent. Moreover, high irradiation dose seemed to affect the protein structure, accounting for the decrease of the breaking strength of gels and for the depreciation of the mechanical behavior of films

  12. Development and Evaluation of Buccal Films Based on Chitosan for the Potential Treatment of Oral Candidiasis.

    Science.gov (United States)

    Tejada, G; Barrera, M G; Piccirilli, G N; Sortino, M; Frattini, A; Salomón, C J; Lamas, María C; Leonardi, Darío

    2017-05-01

    In this work, chitosan films were prepared by a casting/solvent evaporation methodology using pectin or hydroxypropylmethyl cellulose to form polymeric matrices. Miconazole nitrate, as a model drug, was loaded into such formulations. These polymeric films were characterized in terms of mechanical properties, adhesiveness, and swelling as well as drug release. Besides, the morphology of raw materials and films was investigated by scanning electron microscopy; interactions between polymers were analyzed by infrared spectroscopy and drug crystallinity studied by differential scanning calorimetry and X-ray diffraction. In addition, antifungal activity against cultures of the five most important fungal opportunistic pathogens belonging to Candida genus was investigated. Chitosan:hydroxypropylmethyl cellulose films were found to be the most appropriate formulations in terms of folding endurance, mechanical properties, and adhesiveness. Also, an improvement in the dissolution rate of miconazole nitrate from the films up to 90% compared to the non-loaded drug was observed. The in vitro antifungal activity showed a significant activity of the model drug when it is loaded into chitosan films. These findings suggest that chitosan-based films are a promising approach to deliver miconazole nitrate for the treatment of candidiasis.

  13. Amorphous and crystalline In_2O_3-based transparent conducting films for photovoltaics

    International Nuclear Information System (INIS)

    Koida, Takashi

    2017-01-01

    We reported solar cells with reduced electrical and optical losses using hydrogen-doped In_2O_3 (In_2O_3:H) transparent conducting layers with low sheet resistance and high transparence characteristics. The transparent conducting oxide (TCO) films were prepared by solid-phase crystallization of amorphous (a-) In_2O_3:H films grown by magnetron sputtering. The polycrystalline (poly-) In_2O_3:H films exhibited electron mobilities (over 100 cm"2V"-"1 s"-"1) 2 and 3 times greater than those of conventional TCO films. This paper describes (i) the current status of the electrical properties of In_2O_3-based TCO; (ii) the structural and optoelectrical properties of the a-In_2O_3:H and poly-In_2O_3:H films, focusing on the inhomogeneity and stability characteristics of the films; and (iii) the electrical properties of bilayer TCO. The potential of these high mobility TCO films for solar cells was also described. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  14. Development and Characterization of Edible Films Based on Fruit and Vegetable Residues.

    Science.gov (United States)

    Andrade, Roberta M S; Ferreira, Mariana S L; Gonçalves, Édira C B A

    2016-02-01

    Edible films were developed from the solid residue of the processing of whole fruits and vegetables. The solid residue, processed into flour (FVR flour) was chemically and structurally characterized by microstructure, elemental composition, structural links, and moisture sorption isotherm. Films were prepared by casting using aqueous extracts of 8% and 10% of flour (w/w) and characterized in terms of thickness, water solubility, mechanical properties, water vapor permeability, and Fourier transform infrared (FTIR). The analysis of microstructure and elemental composition, performed on flour (mean particle size 350 μm), showed an essentially granular aspect, with the presence of fibrous particles having potassium as one of the most abundant elements. FTIR results showed similarity between the characteristic bands of other raw materials used in edible films. The sorption isotherm of FVR flour showed a typical profile of foods rich in soluble components, such as sugars. Dried films presented an average thickness of 0.263 ± 0.003 mm, a homogenous aspect, bright yellow color, pronounced fruit flavor, and high water solubility. The FTIR spectra of the edible films revealed that addition of potato skin flour did not change the molecular conformation. Moreover, the films presented low tensile strength at break when compared with fruit starch-based films. © 2016 Institute of Food Technologists®

  15. Leaching-resistant carrageenan-based colorimetric oxygen indicator films for intelligent food packaging.

    Science.gov (United States)

    Vu, Chau Hai Thai; Won, Keehoon

    2014-07-23

    Visual oxygen indicators can give information on the quality and safety of packaged food in an economic and simple manner by changing color based on the amount of oxygen in the packaging, which is related to food spoilage. In particular, ultraviolet (UV)-activated oxygen indicators have the advantages of in-pack activation and irreversibility; however, these dye-based oxygen indicator films suffer from dye leaching upon contact with water. In this work, we introduce carrageenans, which are natural sulfated polysaccharides, to develop UV-activated colorimetric oxygen indicator films that are resistant to dye leakage. Carrageenan-based indicator films were fabricated using redox dyes [methylene blue (MB), azure A, and thionine], a sacrificial electron donor (glycerol), an UV-absorbing photocatalyst (TiO2), and an encapsulation polymer (carrageenan). They showed even lower dye leakage in water than conventional oxygen indicator films, owing to the electrostatic interaction of anionic carrageenan with cationic dyes. The MB/TiO2/glycerol/carrageenan oxygen indicator film was successfully bleached upon UV irradiation, and it regained color very rapidly in the presence of oxygen compared to the other waterproof oxygen indicator films.

  16. Near infrared reflectance spectroscopy for the fast identification of PVC-based films.

    Science.gov (United States)

    Laasonen, M; Rantanen, J; Harmia-Pulkkinen, T; Michiels, E; Hiltunen, R; Räsänen, M; Vuorela, H

    2001-07-01

    Near infrared (NIR) reflectance spectroscopy was used to develop a non-destructive and rapid qualitative method for the analysis of plastic films used by the pharmaceutical industry for blistering. Three types of films were investigated: 250 microm PVC [poly(vinyl chloride)] films, 250 microm PVC films coated with 40 g m(-2) of PVDC [poly(vinylidene dichloride)] and 250 microm PVC films coated with 5 g m(-2) of TE (Thermoelast) and 90 g m(-2) of PVDC. Three analyses were carried out using different pre-treatment options and a PLS (partial least squares) algorithm. Each analysis was aimed at identifying one type of film and rejecting all types of false sample (different thickness, colour or layer). True and false samples from four plastics manufacturers were included in the calibration sets in order to obtain robust methods that were suitable regardless of the supplier. Specificity was demonstrated by testing validation sets against the methods. The tests showed 0% of type I (false negative identification) and 1% of type II errors (false positive identification) for the PVC method, 13 and 3%, respectively, for the PVC-PVDC method and no error for the PVC-TE-PVDC method. Type II errors, mostly due to the slight sensitivity of the methods to film thickness, are easily corrected by simple thickness measurements. This study demonstrates that NIR spectroscopy is an excellent tool for the identification of PVC-based films. The three methods can be used by the pharmaceutical industry or plastics manufacturers for the quality control of films used in blister packaging.

  17. Electrochemical Impedance Spectroscopic Analysis of RuO2 Based Thick Film pH Sensors

    International Nuclear Information System (INIS)

    Manjakkal, Libu; Djurdjic, Elvira; Cvejin, Katarina; Kulawik, Jan; Zaraska, Krzysztof; Szwagierczak, Dorota

    2015-01-01

    The conductimetric interdigitated thick film pH sensors based on RuO 2 were fabricated and their electrochemical reactions with solutions of different pH values were studied by electrochemical impedance spectroscopy (EIS) technique. The microstructural properties and composition of the sensitive films were examined by scanning electron microscopy, X-ray energy dispersive spectroscopy and Raman spectroscopy. The EIS analysis of the sensor was carried out in the frequency range 10 mHz–2 MHz for pH values of test solutions 2–12. The electrical parameters of the sensor were found to vary with changing pH. The conductance and capacitance of the film were distinctly dependent on pH in the low frequency range. The Nyquist and Bode plots derived from the impedance data for the metal oxide thick film pH sensor provided information about the underlying electrochemical reactions

  18. Multifunctional thick-film structures based on spinel ceramics for environment sensors

    Energy Technology Data Exchange (ETDEWEB)

    Vakiv, M; Hadzaman, I; Klym, H; Shpotyuk, O [Institute of Materials of SRC ' Carat' , 202 Stryjska str., Lviv, 79031 (Ukraine); Brunner, M, E-mail: shpotyuk@novas.lviv.ua, E-mail: klymha@yahoo.com [Fachhochschule Koeln/University of Applied Sciences, 2 Betzdorfer str., Koeln, 50679 (Germany)

    2011-04-01

    Temperature sensitive thick films based on spinel-type NiMn{sub 2}O{sub 4}-CuMn{sub 2}O{sub 4}-MnCo{sub 2}O{sub 4} manganites with p- and p{sup +}-types of electrical conductivity and their multilayer p{sup +}-p structures were studied. These thick-film elements possess good electrophysical characteristics before and after long-term ageing test at 170 deg. C. It is shown that degradation processes connected with diffusion of metallic Ag into film grain boundaries occur in one-layer p-and p{sup +}-conductive films. Some part of the p{sup +}-p structures were of high stability, the relative electrical drift being no more than 1 %.

  19. Hydroxylated graphene-based flexible carbon film with ultrahigh electrical and thermal conductivity.

    Science.gov (United States)

    Ding, Jiheng; Ur Rahman, Obaid; Zhao, Hongran; Peng, Wanjun; Dou, Huimin; Chen, Hao; Yu, Haibin

    2017-09-29

    Graphene-based films are widely used in the electronics industry. Here, surface hydroxylated graphene sheets (HGS) have been synthesized from natural graphite (NG) by a rapid and efficient molten hydroxide-assisted exfoliation technique. This method enables preparation of aqueous dispersible graphene sheets with a high dispersed concentration (∼10.0 mg ml -1 ) and an extraordinary production yield (∼100%). The HGS dispersion was processed into graphene flexible film (HGCF) through fast filtration, annealing treatment and mechanical compression. The HGS endows graphene flexible film with a high electrical conductivity of 11.5 × 10 4 S m -1 and a superior thermal conductivity of 1842 W m -1 K -1 . Simultaneously, the superflexible HGCF could endure 3000 repeated cycles of bending or folding. As a result, this graphene flexible film is expected to be integrated into electronic packaging and high-power electronics applications.

  20. Highly conductive, transparent flexible films based on open rings of multi-walled carbon nanotubes

    International Nuclear Information System (INIS)

    Ko, Wen-Yin; Su, Jun-Wei; Guo, Chian-Hua; Fu, Shu-Juan; Hsu, Chuen-Yuan; Lin, Kuan-Jiuh

    2011-01-01

    Open rings of multi-walled carbon nanotubes were stacked to form porous networks on a poly(ethylene terephthalate) substrate to form a flexible conducting film (MWCNT-PET) with good electrical conductivity and transparency by a combination of ultrasonic atomization and spin-coating technique. To enhance the electric flexibility, we spin-coated a cast film of poly(vinyl alcohol) onto the MWCNT-PET substrate, which then underwent a thermo-compression process. Field-emission scanning electron microscopy of the cross-sectional morphology illustrates that the film has a robust network with a thickness of ∼ 175 nm, and it remarkably exhibits a sheet resistance of approximately 370 Ω/sq with ∼ 77% transmittance at 550 nm even after 500 bending cycles. This electrical conductivity is much superior to that of other MWCNT-based transparent flexible films.

  1. Optimization of Biopolymer Based Transdermal Films of Metoclopramide as an Alternative Delivery Approach

    Directory of Open Access Journals (Sweden)

    Betül Aktar

    2014-05-01

    Full Text Available The objectives of this study were to develop and to characterize sodium alginate based matrix-type transdermal films of metoclopramide hydrochloride (MTC in order to improve patient compliance to treatment. The suitability of sodium alginate was shown to be a natural film former in terms of the physicochemical, mechanical, and bioadhesive features of the MTC loaded transdermal films. Terpinolene provided the highest drug release among the different terpenes (nerolidol, eucalyptol, dl-limonene, or terpinolene assessed as enhancer. Attenuated Total Reflectance Infrared (ATR-FTIR spectroscopy analysis performed to evaluate the effect of the transdermal films on skin barrier confirmed enhancer induced lipid bilayer disruption in stratum corneum, indicating its permeation enhancement effect.

  2. Thermal recrystallization of physical vapor deposition based germanium thin films on bulk silicon (100)

    KAUST Repository

    Hussain, Aftab M.

    2013-08-16

    We demonstrate a simple, low-cost, and scalable process for obtaining uniform, smooth surfaced, high quality mono-crystalline germanium (100) thin films on silicon (100). The germanium thin films were deposited on a silicon substrate using plasma-assisted sputtering based physical vapor deposition. They were crystallized by annealing at various temperatures ranging from 700 °C to 1100 °C. We report that the best quality germanium thin films are obtained above the melting point of germanium (937 °C), thus offering a method for in-situ Czochralski process. We show well-behaved high-κ /metal gate metal-oxide-semiconductor capacitors (MOSCAPs) using this film. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Preparation, Characterization, and Electrochromic Properties of Nanocellulose-Based Polyaniline Nanocomposite Films.

    Science.gov (United States)

    Zhang, Sihang; Sun, Gang; He, Yongfeng; Fu, Runfang; Gu, Yingchun; Chen, Sheng

    2017-05-17

    On the basis of nanocellulose obtained by acidic swelling and ultrasonication, rodlike nanocellulose/polyaniline nanocomposites with a core-shell structure have been prepared via in situ polymerization. Compared to pure polyaniline, the nanocomposites show superior film-forming properties, and the prepared nanocomposite films demonstrate excellent electrochemical and electrochromic properties in electrolyte solution. Nanocomposite films, especially the one prepared with 40% polyaniline coated nanocomposite, exhibited faster response time (1.5 s for bleaching and 1.0 s for coloring), higher optical contrast (62.9%), higher coloration efficiency (206.2 cm 2 /C), and more remarkable switching stability (over 500 cycles). These novel nanocellulose-based nanorod network films are promising novel electrochromic materials with excellent properties.

  4. Design and simulation analysis of a novel pressure sensor based on graphene film

    Science.gov (United States)

    Nie, M.; Xia, Y. H.; Guo, A. Q.

    2018-02-01

    A novel pressure sensor structure based on graphene film as the sensitive membrane was proposed in this paper, which solved the problem to measure low and minor pressure with high sensitivity. Moreover, the fabrication process was designed which can be compatible with CMOS IC fabrication technology. Finite element analysis has been used to simulate the displacement distribution of the thin movable graphene film of the designed pressure sensor under the different pressures with different dimensions. From the simulation results, the optimized structure has been obtained which can be applied in the low measurement range from 10hPa to 60hPa. The length and thickness of the graphene film could be designed as 100μm and 0.2μm, respectively. The maximum mechanical stress on the edge of the sensitive membrane was 1.84kPa, which was far below the breaking strength of the silicon nitride and graphene film.

  5. Biodegradable Composite Films based on κ-carrageenan Reinforced by Cellulose Nanocrystal from Kenaf Fibers

    Directory of Open Access Journals (Sweden)

    Siti Zarina

    2014-11-01

    Full Text Available Through alkali treatment, bleaching, and sulfuric acid hydrolysis, cellulose nanocrystals (CNCs were prepared from kenaf fibers and were used as reinforcement materials in biocomposites based on κ-carrageenan. Biocomposites in the form of films were prepared by solution casting of a mixture of κ-carrageenan, glycerol, and various amounts of CNCs (0 to 8 wt%. Fourier transform infrared spectroscopy (FTIR revealed that alkali treatment followed by bleaching totally removed lignin and hemicellulose from the kenaf. Morphological analysis of the fibers, cellulose, and κ-carrageenan of biocomposite films were carried out using field emission scanning electron microscopy (FESEM and transmission electron microscopy (TEM. The effects of filler content on the mechanical and thermal stability of the k-carrageenan biocomposite films were analyzed through tensile strength measurements and thermogravimetric analysis (TGA. At an optimum CNC content of 4%, the κ-carrageenan biocomposite films showed good dispersion, superior mechanical properties, and improved thermal stability.

  6. Structural and optical investigation of Te-based chalcogenide thin films

    Energy Technology Data Exchange (ETDEWEB)

    Sharma, Rita, E-mail: reetasharma2012@gmail.com; Sharma, Shaveta; Thangaraj, R.; Mian, M. [Semiconductors Laboratory, Department of Physics, GND University, Amritsar (India); Chander, Ravi [Applied Science Deptt. Govt. Polytechnic College Amritsar (India); Kumar, Praveen [Department of Physics, DAV University, Sarmastipur, Jalandhar-144012 (India)

    2015-05-15

    We report the structural and optical properties of thermally evaporated Bi{sub 2}Te{sub 3}, In{sub 2}Te{sub 3} and InBiTe{sub 3} films by using X-ray diffraction, optical and Raman Spectroscopy techniques. The as-prepared thin films were found to be Semi-crystalline by X-ray diffraction. Particle Size and Strain has been calculated from XRD data. The optical constants, film thickness, refractive index and optical band gap (E{sub g}) has been reported for In{sub 2}Te{sub 3}, InBiTe{sub 3} films. Raman Spectroscopy was performed to investigate the effect of Bi, In, on lattice vibration and chemical bonding in Te based chalcogenide glassy alloys.

  7. Polyurethane-acrylate-based hydrophobic film: Facile fabrication, characterization, and application

    Science.gov (United States)

    Park, Jongsung; Nguyen, Bui Quoc Huy; Kim, Ji-Kwan; Shanmugasundaram, Arunkumar; Lee, Dong-Weon

    2018-06-01

    Polyurethane-acrylate (PUA) is a versatile UV-curable polymer with a short curing time at room temperature, whose surface structure can be flexibly modified by applying various micropatterns. In this paper, we propose a facile and cost-effective fabrication method for the continuous production of an optically transparent PUA-based superhydrophobic thin film. Poly(dimethylsiloxane) (PDMS) was employed as a soft mold for the fabrication of PUA films through the roll-to-roll technique. In addition, nanosilica was spray-coated onto the PUA surface to further improve the hydrophobicity. The fabricated PUA thin film showed the highest static water contact angle (WCA) of ∼140°. The high durability of the PUA film was also demonstrated through mechanical impacting tests. Furthermore, only ∼2% of voltage loss was observed in the solar panel covered with the PUA-based superhydrophobic film. These obtained results indicate the feasibility of applying the film as a protective layer in applications requiring a high transparency and a self-cleaning effect.

  8. Effects of accelerated degradation on metal supported thin film-based solid oxide fuel cell

    DEFF Research Database (Denmark)

    Reolon, R. P.; Sanna, S.; Xu, Yu

    2018-01-01

    A thin film-based solid oxide fuel cell is deposited on a Ni-based metal porous support by pulsed laser deposition with a multi-scale-graded microstructure design. The fuel cell, around 1 μm in thickness, is composed of a stabilized-zirconia/doped-ceria bi-layered dense electrolyte and nanostruct......A thin film-based solid oxide fuel cell is deposited on a Ni-based metal porous support by pulsed laser deposition with a multi-scale-graded microstructure design. The fuel cell, around 1 μm in thickness, is composed of a stabilized-zirconia/doped-ceria bi-layered dense electrolyte......, electrochemical performances are steady, indicating the stability of the cell. Under electrical load, a progressive degradation is activated. Post-test analysis reveals both mechanical and chemical degradation of the cell. Cracks and delamination of the thin films promote a significant nickel diffusion and new...

  9. Machine Vision based Micro-crack Inspection in Thin-film Solar Cell Panel

    Directory of Open Access Journals (Sweden)

    Zhang Yinong

    2014-09-01

    Full Text Available Thin film solar cell consists of various layers so the surface of solar cell shows heterogeneous textures. Because of this property the visual inspection of micro-crack is very difficult. In this paper, we propose the machine vision-based micro-crack detection scheme for thin film solar cell panel. In the proposed method, the crack edge detection is based on the application of diagonal-kernel and cross-kernel in parallel. Experimental results show that the proposed method has better performance of micro-crack detection than conventional anisotropic model based methods on a cross- kernel.

  10. An energy landscape based approach for studying supercooled liquid and glassy thin films

    Science.gov (United States)

    Shah, Pooja; Mittal, Jeetain; Truskett, Thomas M.

    2004-03-01

    Materials in confined spaces are important in science and technology. Examples include biological fluids in membranes, liquids trapped in porous rocks, and thin-film materials used in high-resolution patterning technologies. However, few reliable rules exist to predict how the properties of materials will be affected by thin-film confinement. We have recently shown that the potential energy landscape formalism can be used to study, by both theory [1] and simulation [2], how the behavior of thin-film materials depends on sample dimensions and film-substrate interactions. Our landscape-based mean-field theory [1] can be used to study both the thermodynamic properties and the ideal glass transition of thin films. It predicts that, in the case of neutral or repulsive walls, the ideal glass transition temperature is lowered by decreasing film thickness. This is in qualitative agreement with experimental trends for the kinetic glass transition in confined fluids. Landscape-based approaches are also valuable for understanding the structural and mechanical properties of thin-film glasses. We demonstrate how the concept of an "equation of state of the energy landscape" [3] can be generalized to thin films [1, 2], where it gives insights into potential molecular mechanisms of tensile strength. [1] T. M. Truskett and V. Ganesan, J. Chem. Phys. 119, 1897-1900(2003); J. Mittal, P. Shah and T. M. Truskett, to be submitted to Langmuir. [2] P. Shah and T. M. Truskett, to be submitted to J. Phys. Chem. B. [3] S. Sastry, P. G. Debenedetti and F. H. Stillinger, Phys. Rev. E 56, 5533 (1997)

  11. Ultrathin TaOx film based photovoltaic device

    International Nuclear Information System (INIS)

    Tyagi, Pawan

    2011-01-01

    Application of the economical metal oxide thin-film photovoltaic devices is hindered by the poor energy efficiency. This paper investigates the photovoltaic effect with an ultrathin tantalum oxide (TaOx) tunnel barrier, formed by the plasma oxidation of a pre-deposited tantalum (Ta) film. These ∼ 3 nm TaOx tunnel barriers showed approximately 160 mV open circuit voltage and 3-5% energy efficiency, for varying light intensity. The ultrathin TaOx (∼ 3 nm) could absorb approximately 12% of the incident light radiation in 400-1000 nm wavelength range; this strong light absorbing capability was found to be associated with the dramatically large extinction coefficient. Spectroscopic ellipsometry revealed that the extinction coefficient of 3 nm TaOx was ∼ 0.2, two orders higher than that of tantalum penta oxide (Ta 2 O 5 ). Interestingly, refractive index of this 3 nm thick TaOx was comparable with that of stochiometeric Ta 2 O 5 . However, heating and prolonged high-intensity light exposure deteriorated the photovoltaic effect in TaOx junctions. This study provides the basis to explore the photovoltaic effect in a highly economical and easily processable ultrathin metal oxide tunnel barrier or analogous systems.

  12. New Fast Response Thin Film-Based Superconducting Quench Detectors

    CERN Document Server

    Dudarev, A; van de Camp, W; Ravaioli, E; Teixeira, A; ten Kate, H H J

    2014-01-01

    Quench detection on superconducting bus bars and other devices with a low normal zone propagation velocity and low voltage build-up is quite difficult with conventional quench detection techniques. Currently, on ATLAS superconducting bus bar sections, superconducting quench detectors (SQD) are mounted to detect quench events. A first version of the SQD essentially consists of an insulated superconducting wire glued to a superconducting bus line or windings, which in the case of a quench rapidly builds up a relatively high resistance that can be easily and quietly detected. We now introduce a new generation of drastically improved SQDs. The new version makes the detection of quenches simpler, more reliable, and much faster. Instead of a superconducting wire, now a superconducting thin film is used. The layout of the sensor shows a meander like pattern that is etched out of a copper coated 25 mu m thick film of Nb-Ti glued in between layers of Kapton. Since the sensor is now much smaller and thinner, it is easi...

  13. Methodology for cost analysis of film-based and filmless portable chest systems

    Science.gov (United States)

    Melson, David L.; Gauvain, Karen M.; Beardslee, Brian M.; Kraitsik, Michael J.; Burton, Larry; Blaine, G. James; Brink, Gary S.

    1996-05-01

    Many studies analyzing the costs of film-based and filmless radiology have focused on multi- modality, hospital-wide solutions. Yet due to the enormous cost of converting an entire large radiology department or hospital to a filmless environment all at once, institutions often choose to eliminate film one area at a time. Narrowing the focus of cost-analysis may be useful in making such decisions. This presentation will outline a methodology for analyzing the cost per exam of film-based and filmless solutions for providing portable chest exams to Intensive Care Units (ICUs). The methodology, unlike most in the literature, is based on parallel data collection from existing filmless and film-based ICUs, and is currently being utilized at our institution. Direct costs, taken from the perspective of the hospital, for portable computed radiography chest exams in one filmless and two film-based ICUs are identified. The major cost components are labor, equipment, materials, and storage. Methods for gathering and analyzing each of the cost components are discussed, including FTE-based and time-based labor analysis, incorporation of equipment depreciation, lease, and maintenance costs, and estimation of materials costs. Extrapolation of data from three ICUs to model hypothetical, hospital-wide film-based and filmless ICU imaging systems is described. Performance of sensitivity analysis on the filmless model to assess the impact of anticipated reductions in specific labor, equipment, and archiving costs is detailed. A number of indirect costs, which are not explicitly included in the analysis, are identified and discussed.

  14. Electrochemical characterization of Zr-based thin film metallic glass in hydrochloric aqueous solution

    International Nuclear Information System (INIS)

    Chuang, Ching-Yen; Liao, Yi-Chia; Lee, Jyh-Wei; Li, Chia-Lin; Chu, Jinn P.; Duh, Jenq-Gong

    2013-01-01

    Recently thin film metallic glass represents a class of promising engineering materials for structural applications. In this work, the Zr-based thin film metallic glass (TFMG) was fabricated on the Si and AISI 420 substrates using a Zr–Cu–Ni–Al alloy and pure Zr metal targets by a pulsed DC magnetron sputtering system. The chemical compositions, crystalline structures, microstructures and corrosion behavior in hydrochloric (HCl) aqueous solutions of Zr-based TFMGs were investigated. The results showed that the surface morphologies of Zr-based TFMG were very smooth. A compact and dense structure without columnar structure was observed. The amorphous structure of Zr-based TFMG was characterized by the X-ray diffractometer and transmission electron microscopy analyses. After the potentiodynamic polarization test, the better corrosion resistance was achieved for the Zr-based TFMG coated AISI 420 in 1 mM HCl aqueous solution. Based on the surface morphologies and chemical analysis results of the corroded surfaces, the pitting, crevice corrosion and filiform corrosion were found. The corrosion mechanisms of the Zr-based TFMG were discussed in this work. - Highlights: ► Zr-based thin film metallic glass with amorphous structure. ► Better corrosion resistance of Zr-based thin film metallic glass observed. ► Pitting, crevice and filiform corrosion reactions revealed. ► The Cu-rich corrosion products found in the pit. ► Nanowire and flaky corrosion products formed adjacent to the filiform corrosion path

  15. Kirigami-based PVDF thin-film as stretchable strain sensor

    Science.gov (United States)

    Hu, Nan; Chen, Dajing; Hao, Nanjing; Huang, Shicheng; Yu, Xiaojiao; Zhang, John X. J.; Chen, Zi

    Kirigami, as the sister of the origami, involves cutting of 2D sheets to form complex 3D geometries with out-of-plane patterns. Motivated by the development of the high-stretchable biomedical devices, we explore the stretchability of the kirigami-based PVDF thin film under tension. Our structural prototypes include a set of 2D geometry with kirigami-based pattern cutting on PVDF thin films. We first used paper models to generate a wide range of cutting patterns to study the deformation under compression tests, the results of which are compared with finite element simulations. We then proceeded to test different kirigami-based designs to identify geometric parameters that can tune the post-buckling response and strain distribution. Next, we fabricated and tested the PVDF thin film with kirigami pattern. Experiments showed that the PVDF film in the absence of cutting can be stretched to a limited extent and will break upon further stretching. In contrast, the kirigami-based films can be stretched up to 100% without failure. Our designs demonstrate the ability to significantly improve the strain range of the structure and sensing ability of a sensor. We envision a promising future to use this class of structural elements to develop highly stretchable materials, structures, and devices. Z.C. acknowledges the Society in Science-Branco Weiss fellowship, administered by ETH Zürich. J.X.J.Z. acknowledges the NIH Director's Transformative Research Award (1R01 OD022910-01).

  16. A piezo-film-based measurement system for global haemodynamic assessment

    International Nuclear Information System (INIS)

    Clemente, Fabrizio; Cimmino, Pasquale; Arpaia, Pasquale

    2010-01-01

    A non-invasive piezo-film-based measurement method for haemodynamic assessment is proposed. The design of a system, able to reconstruct the blood pressure waveform online by dealing with problems arising from the piezo-film capacitive nature in the targeted frequency range (from quasi-dc up to 12 Hz), is illustrated. The system is based on a commercial piezo-film placed easily on the radial artery with a special brace without any discomfort for the patient. The analogical conditioning circuit and digital signal processing are continuously tuned with the signal from the sensor to reconstruct the blood pressure signal online. Diagnostic schema, based on physio-pathological models, have been implemented in order to compute online trends of max[dP(t)/d(t)] and volemic status highly useful for the intensivist and anaesthesiologist. The system was characterized by numerical simulation and experimental in vivo comparison to the traditional reference system

  17. Polypyrrole-polyvinyl sulphonate film based disposable nucleic acid biosensor

    Energy Technology Data Exchange (ETDEWEB)

    Prabhakar, Nirmal [Biomolecular Electronics and Conducting Polymer Research Group, National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012 (India); Centre for Biomedical Engineering, Indian Institute of Technology, Hauz Khas, New Delhi 110016 (India); Arora, Kavita [Biomolecular Electronics and Conducting Polymer Research Group, National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012 (India); Singh, Surinder P. [Biomolecular Electronics and Conducting Polymer Research Group, National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012 (India); Pandey, Manoj K. [Biomolecular Electronics and Conducting Polymer Research Group, National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012 (India); Singh, Harpal [Centre for Biomedical Engineering, Indian Institute of Technology, Hauz Khas, New Delhi 110016 (India); Malhotra, Bansi D. [Biomolecular Electronics and Conducting Polymer Research Group, National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110012 (India)]. E-mail: bansi.malhotra@gmail.com

    2007-04-18

    Double stranded calf thymus deoxyribonucleic acid entrapped polypyrrole-polyvinyl sulphonate (dsCT-DNA-PPy-PVS) films fabricated onto indium-tin-oxide (ITO) coated glass plates have been used to detect organophosphates such as chlorpyrifos and malathion. These disposable dsCT-DNA-PPy-PVS/ITO bioelectrodes have been characterized using cyclic voltammetry, Fourier-transform-infra-red (FTIR) spectroscopy and atomic force microscopy (AFM), respectively. These biosensing electrodes have a response time of 30 s, are stable for about 5 months when stored in desiccated conditions at 25 deg. C and can be used to amperometrically detect chlorpyrifos (0.0016-0.025 ppm) and malathion (0.17-5.0), respectively. The additive effect of these pesticides on the amperometric response of the disposable dsCT-DNA-PPy-PVS/ITO bioelectrodes has also been investigated.

  18. Carbon-based sputtered coatings for enhanced chitosan-based films properties

    Science.gov (United States)

    Fernandes, C.; Calderon V., S.; Ballesteros, Lina F.; Cerqueira, Miguel A.; Pastrana, L. M.; Teixeira, José A.; Ferreira, P. J.; Carvalho, S.

    2018-03-01

    In order to make bio-based packaging materials competitive in comparison to petroleum-based one, some of their properties need to be improved, among which gas permeability is of crucial importance. Thus, in this work, carbon-based coatings were applied on chitosan-based films by radiofrequency reactive magnetron sputtering aiming to improve their barrier properties. Chemical and morphological properties were evaluated in order to determine the effect of the coatings on the chemical structure, surface hydrophobicity and barrier properties of the system. Chemical analysis, performed by electron energy loss spectroscopy and Fourier transform infrared spectroscopy, suggests similar chemical characteristics among all coatings although higher incorporation of hydrogen as the acetylene flux increases was observed. On the other hand, scanning transmission electron microscopy revealed that the porosity of the carbon layer can be tailored by the acetylene flux. More importantly, the chitosan oxygen permeability showed a monotonic reduction as a function of the acetylene flux. This study opens up new opportunities to apply nanostructured coatings on bio-based polymer for enhanced oxygen barrier properties.

  19. Magnetic and other properties and sputtering behavior of Co-base amorphous alloy films

    International Nuclear Information System (INIS)

    Hayashi, K.; Hayakawa, M.; Ochiai, Y.; Matsuda, H.; Ishikawa, W.; Iwasaki, Y.; Aso, K.

    1987-01-01

    Magnetic and other properties of Co-base amorphous alloy films prepared by sputtering are investigated. A detailed magnetic phase diagram with saturation magnetic flux density, crystallization temperature, and zero-magnetostrictive line on Co-Ta-Zr amorphous alloys were obtained, and the technical knowhow to make a film with well-reproducible characteristics by widely changing the sputtering conditions was related with these physical properties. Especially on alloy sputtering, a phenomenological model for elucidating a composition difference between film and target is presented. After these studies, the film characteristics of B/sub s/ = 12 kG, T/sub x/ = 450 0 C, chemical bondλ/sub s/chemical bond -8 , H/sub c/<10 mOe, and permeabilities of μ(1 MHz) = 7000, μ(100 MHz) = 2000 for the single film of 2 μm in thickness and of μ(1 MHz) = 4000, μ(100 MHz) = 800 for the insulator-sandwiched multilayered film of 10 μm are obtained, and these well-balanced values enable us to apply the materials for high-frequency recording head

  20. A film-based wall shear stress sensor for wall-bounded turbulent flows

    Science.gov (United States)

    Amili, Omid; Soria, Julio

    2011-07-01

    In wall-bounded turbulent flows, determination of wall shear stress is an important task. The main objective of the present work is to develop a sensor which is capable of measuring surface shear stress over an extended region applicable to wall-bounded turbulent flows. This sensor, as a direct method for measuring wall shear stress, consists of mounting a thin flexible film on the solid surface. The sensor is made of a homogeneous, isotropic, and incompressible material. The geometry and mechanical properties of the film are measured, and particles with the nominal size of 11 μm in diameter are embedded on the film's surface to act as markers. An optical technique is used to measure the film deformation caused by the flow. The film has typically deflection of less than 2% of the material thickness under maximum loading. The sensor sensitivity can be adjusted by changing the thickness of the layer or the shear modulus of the film's material. The paper reports the sensor fabrication, static and dynamic calibration procedure, and its application to a fully developed turbulent channel flow at Reynolds numbers in the range of 90,000-130,000 based on the bulk velocity and channel full height. The results are compared to alternative wall shear stress measurement methods.

  1. Low-level dosimetry based on activation analysis of badge film, 1

    International Nuclear Information System (INIS)

    Morikawa, Kaoru; Yamashita, Kazuya; Inamoto, Kazuo; Maeda, Masayuki; Sato, Takashi; Ono, Koichi.

    1988-01-01

    Underexposed badge film contains a minor quantity of silver which corresponds to the low radiation dose even after completion of the photographic densitometry ; however, it cannot be detected with a photographic densitometer. We intended to clarify the minor silver content based on radioactivation analysis with thermal neutrons at KUR (Kyoto University Research Reactor). The natural silver consists of two stable nuclides, i.e., 107 Ag and 109 Ag. These can be activated with irradiation of thermal neutrons to two radionuclides, i.e., 108 Ag and 110 Ag. In this paper, through the activation analysis of an underexposed badge film, methods of measurements are shown regarding both 108 Ag produced by the 107 Ag (n, γ) reaction and 110 Ag by the 109 Ag (n, γ). After underexposed badge films were irradiated with thermal neutrons, some gamma-rays emitted from the radionuclides in the activated films were measured with a high pure Ge detector or a NaI (Tl) scintillation detector. The following results were obtained: (1) several elements such as silver, iodine, gold, antimony, manganese and copper were detected by activation analyses of films exposed to low level 60 Co gamma-rays, (2) the exposure vs 108 Ag or 110 Ag activity curve was linear in the lower dose range of 60 Co gamma-rays. These data indicate that low level radiation doses, which is indeterminable by ordinary photographic densitometry, can be estimated by activation analysis of silver atoms in badge films. (author)

  2. Graphene-based LbL deposited films: further study of electrical and gas sensing properties

    Directory of Open Access Journals (Sweden)

    Nabok A.

    2017-01-01

    Full Text Available Graphene-surfactant composite materials obtained by the ultrasonic exfoliation of graphite powder in the presence of ionic surfactants (either CTAB or SDS were utilised to construct thin films using layer-by-layer (LbL electrostatic deposition technique. A series of graphene-based thin films were made by alternating layers of either graphene-SDS with polycations (PEI or PAH or graphene-CTAB with polyanions (PSS. Also, graphene-phthalocyanine composite films were produced by alternating layers of graphene-CTAB with tetrasulfonated nickel phthalocyanine. Graphene-surfactant LbL films exhibited good electric conductivity (about 0.1 S/cm of semiconductor type with a band gap of about 20 meV. Judging from UV-vis spectra measurements, graphene-phthalocyanine LbL films appeared to form joint π-electron system. Gas sensing testing of such composite films combining high conductivity of graphene with the gas sensing abilities of phthalocyanines showed substantial changes (up to 10% in electrical conductivity upon exposure to electro-active gases such as HCl and NH3.

  3. Laser Based Color Film Recorder System With GaAs Microlaser

    Science.gov (United States)

    Difrancesco, David J.

    1989-07-01

    In 1984 Pixar's research and development group built and applied to the motion-picture arts at Lucasfilm's ILM facility a three color laser based film scanner/recorder system. The digital film printer is capable of reading and writing 35mm film formats on a variety of film stocks. The system has been used in award-winning special-effects work, and has been operated in a normal production environment since that time. The primary objective was to develop a full color high resolution system, free from scan artifacts, enabling traditionally photographed motion-picture film to be inter-cut with digital raster image photography. Its use is applied to the art of blue-screen traveling-matte cinematography for motion pic-ture special effects. The system was designed using the Pixar Image Computer and conventional gas laser technology as the illumination source. This paper will discuss recent experimental work in the application of GaAs microlaser technology to a digital film printing system of the future.

  4. Properties of pentacene-based films prepared using a heated tungsten mesh

    Energy Technology Data Exchange (ETDEWEB)

    Heya, Akira, E-mail: heya@eng.u-hyogo.ac.jp; Matsuo, Naoto

    2014-11-03

    A heated tungsten (W) mesh, set between a pentacene source and a substrate in a vacuum chamber, was used to prepare a bulk-phase pentacene film and a pentacene-based organic semiconductor film. Since the pentacene molecules come into contact with the heated W mesh before reaching the substrate, their thermal energy is increased prior to deposition. As the mesh temperature was increased from 23 to 1200 °C, the intensity ratio of bulk to thin-film phases increased from 0 to 9.7. Above 1300 °C there is a notable decomposition reaction, the products of which were identified as dihydropentacene, p-distrylbenzene, and 2,2′-dimethyl-1,1′-binaphthalene. These decomposed precursors are expected to provide a potential source of large graphene sheets and graphene nanoribbons. - Highlights: • Organic semiconductor films were prepared using pentacene, H{sub 2} gas, and heated W mesh. • The effect of mesh temperature on film deposition was observed. • Pentacene decomposition above 1300 °C provides graphene precursors. • A method is proposed for controlling the sheet resistance of organic films.

  5. Thin film polarizer and color filter based on photo-polymerizable nematic liquid crystal

    Science.gov (United States)

    Mohammadimasoudi, Mohammad; Neyts, Kristiaan; Beeckman, Jeroen

    2015-03-01

    We present a method to fabricate a thin film color filter based on a mixture of photo-polymerizable liquid crystal and chiral dopant. A chiral nematic liquid crystal layer reflects light for a certain wavelength interval Δλ (= Δn.P) with the period and Δn the birefringence of the liquid crystal. The reflection band is determined by the chiral dopant concentration. The bandwidth is limited to 80nm and the reflectance is at most 50% for unpolarized incident light. The thin color filter is interesting for innovative applications like polarizer-free reflective displays, polarization-independent devices, stealth technologies, or smart switchable reflective windows to control solar light and heat. The reflected light has strong color saturation without absorption because of the sharp band edges. A thin film polarizer is developed by using a mixture of photo-polymerizable liquid crystal and color-neutral dye. The fabricated thin film absorbs light that is polarized parallel to the c axis of the LC. The obtained polarization ratio is 80% for a film of only 12 μm. The thin film polarizer and the color filter feature excellent film characteristics without domains and can be detached from the substrate which is useful for e.g. flexible substrates.

  6. Study on sodium water glass-based anti-reflective film and its application in dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Q.Z. [Key Laboratory of Renewable Energy, Guangdong Key Laboratory of New and Renewable Energy Research and Development, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510000 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Shi, J.F., E-mail: shijf@ms.giec.ac.cn [Key Laboratory of Renewable Energy, Guangdong Key Laboratory of New and Renewable Energy Research and Development, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510000 (China); Wang, L.L.; Li, Y.J.; Zhong, L.W. [Key Laboratory of Renewable Energy, Guangdong Key Laboratory of New and Renewable Energy Research and Development, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510000 (China); Xu, G., E-mail: xugang@ms.giec.ac.cn [Key Laboratory of Renewable Energy, Guangdong Key Laboratory of New and Renewable Energy Research and Development, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences, Guangzhou 510000 (China)

    2016-07-01

    In this paper, anti-reflective (AR) films are prepared from sodium water glass with a simple dip-coating method. The effects of SiO{sub 2}/Na{sub 2}O molar ratio, concentration of water glass, and withdrawal speed on the anti-reflection performance of the AR films are systematically studied. The optimized AR film is further applied in dye-sensitized solar cells (DSCs). The optical properties and surface morphology of AR films are analyzed by ultraviolet-visible spectrophotometer, scanning electron microscope, and atomic force microscope. Transmittance of the glass coated with sodium water glass-based AR film is increased by 3.2% when the SiO{sub 2}/Na{sub 2}O molar ratio, concentration, and withdrawal speed equal to 3.8, 5 wt%, and 80 mm/min, respectively. Under this condition, the thickness of the AR film is 127 nm and the AR film has obvious porous structure. In addition, the power conversion efficiency of DSC coated by AR film is increased from 7.92% to 8.24%, compared with the DSC without AR film. - Highlights: • Anti-reflective films are prepared from sodium water glass. • Transmittance of anti-reflective film is increased by 3.2%. • Efficiency of dye-sensitized cell is improved by anti-reflective film.

  7. Study on sodium water glass-based anti-reflective film and its application in dye-sensitized solar cells

    International Nuclear Information System (INIS)

    Huang, Q.Z.; Shi, J.F.; Wang, L.L.; Li, Y.J.; Zhong, L.W.; Xu, G.

    2016-01-01

    In this paper, anti-reflective (AR) films are prepared from sodium water glass with a simple dip-coating method. The effects of SiO_2/Na_2O molar ratio, concentration of water glass, and withdrawal speed on the anti-reflection performance of the AR films are systematically studied. The optimized AR film is further applied in dye-sensitized solar cells (DSCs). The optical properties and surface morphology of AR films are analyzed by ultraviolet-visible spectrophotometer, scanning electron microscope, and atomic force microscope. Transmittance of the glass coated with sodium water glass-based AR film is increased by 3.2% when the SiO_2/Na_2O molar ratio, concentration, and withdrawal speed equal to 3.8, 5 wt%, and 80 mm/min, respectively. Under this condition, the thickness of the AR film is 127 nm and the AR film has obvious porous structure. In addition, the power conversion efficiency of DSC coated by AR film is increased from 7.92% to 8.24%, compared with the DSC without AR film. - Highlights: • Anti-reflective films are prepared from sodium water glass. • Transmittance of anti-reflective film is increased by 3.2%. • Efficiency of dye-sensitized cell is improved by anti-reflective film.

  8. Highly flexible transparent thin film heaters based on silver nanowires and aluminum zinc oxides

    Energy Technology Data Exchange (ETDEWEB)

    Cheong, Hahn-Gil; Kim, Jin-Hoon; Song, Jun-Hyuk; Jeong, Unyong; Park, Jin-Woo, E-mail: jwpark09@yonsei.ac.kr

    2015-08-31

    In this work, we developed highly flexible transparent film heaters (f-TFHs) composed of Ag nanowire networks (AgNWs) and aluminum zinc oxide (AZO). Uniform AgNWs were roll-to-roll coated on polyethylene terephthalate (PET) substrates using the Mayer rod method, and AZO was sputter-deposited atop the AgNWs at room temperature. The sheet resistance (R{sub s}) and transparency (T{sub opt}) of the AZO-coated AgNWs changed only slightly compared with the uncoated AgNWs. AZO is thermally less conductive than the heat pipes, but increases the thermal efficiency of the heaters blocking the heat convection through the air. Based on Joule heating, a higher average film temperature (T{sub ave}) is attained at a fixed electric potential drop between electrodes (ϕ) as the R{sub s} of the film decreases. Our experimental results revealed that T{sub ave} of the hybrid f-TFH is higher than AgNWs when the ratio of the area coverage of AgNWs to AZO is over a certain value. When a ϕ as low as 3 V/cm was applied to 5 cm × 5 cm f-TFHs, the maximum temperature of the hybrid film was over 100 °C, which is greater than that of AgNWs by more than 30 °C. Furthermore, uniform heating throughout the surfaces is achieved in the hybrid films while heating begins in small areas where densities of the nanowires (NWs) are the highest in the bare network. The non-uniform heating decreases the lifetime of f-TFHs by forming hot spots. Cyclic bending test results indicated that the hybrid films were as flexible as the AgNWs, and the R{sub s} of the hybrid films changes only slightly until 5000 cycles. Combined with the high-throughput coating technology presented here, the hybrid films will provide a robust and scalable strategy for large-area f-TFHs with highly enhanced performance. - Highlights: • We developed highly efficient flexible thin film heaters based on Ag nanowires and AZO composites. • In the composite, AZO plays an important role as an insulation blanket to block heat loss to

  9. Disposable urea biosensor based on nanoporous ZnO film fabricated from omissible polymeric substrate

    International Nuclear Information System (INIS)

    Rahmanian, Reza; Mozaffari, Sayed Ahmad; Abedi, Mohammad

    2015-01-01

    In the present study, a facile and simple fabrication method of a semiconductor based urea biosensor was reported via three steps: (i) producing a ZnO–PVA composite film by means of a polymer assisted electrodeposition of zinc oxide (ZnO) on the F-doped SnO 2 conducting glass (FTO) using water soluble polyvinyl alcohol (PVA), (ii) obtaining a nanoporous ZnO film by PVA omission via a subsequent post-treatment by annealing of the ZnO–PVA film, and (iii) preparation of a FTO/ZnO/Urs biosensor by exploiting a nanoporous ZnO film as an efficient and excellent platform area for electrostatic immobilization of urease enzyme (Urs) which was forced by the difference in their isoelectric point (IEP). The characterization techniques focused on the analysis of the ZnO–PVA film surfaces before and after annealing, which had a prominent effect on the porosity of the prepared ZnO film. The surface characterization of the nanostructured ZnO film by a field emission-scanning electron microscopy (FE–SEM), exhibited a film surface area as an effective bio-sensing matrix for enzyme immobilization. The structural characterization and monitoring of the biosensor fabrication was performed using UV–Vis, Fourier Transform Infrared (FT-IR), Raman Spectroscopy, Thermogravimetric Analysis (TGA), Cyclic Voltammetry (CV), and Electrochemical Impedance Spectroscopy (EIS) techniques. The impedimetric results of the FTO/ZnO/Urs biosensor showed a high sensitivity for urea detection within 8.0–110.0 mg dL −1 with the limit of detection as 5.0 mg dL −1 . - Highlights: • Novel disposable impedimetric urea biosensor fabrication based on ZnO–nanoporous transducer • Exploiting omissible PVA polymer as a simple strategy for ZnO–nanoporous film preparation • ZnO–nanoporous film as a good pore framework with large surface area/volume for enzyme immobilization • Application of impedimetric measurement for urea monitoring due to its rapidity, sensitivity, and repeatability

  10. Disposable urea biosensor based on nanoporous ZnO film fabricated from omissible polymeric substrate

    Energy Technology Data Exchange (ETDEWEB)

    Rahmanian, Reza; Mozaffari, Sayed Ahmad, E-mail: mozaffari@irost.ir; Abedi, Mohammad

    2015-12-01

    In the present study, a facile and simple fabrication method of a semiconductor based urea biosensor was reported via three steps: (i) producing a ZnO–PVA composite film by means of a polymer assisted electrodeposition of zinc oxide (ZnO) on the F-doped SnO{sub 2} conducting glass (FTO) using water soluble polyvinyl alcohol (PVA), (ii) obtaining a nanoporous ZnO film by PVA omission via a subsequent post-treatment by annealing of the ZnO–PVA film, and (iii) preparation of a FTO/ZnO/Urs biosensor by exploiting a nanoporous ZnO film as an efficient and excellent platform area for electrostatic immobilization of urease enzyme (Urs) which was forced by the difference in their isoelectric point (IEP). The characterization techniques focused on the analysis of the ZnO–PVA film surfaces before and after annealing, which had a prominent effect on the porosity of the prepared ZnO film. The surface characterization of the nanostructured ZnO film by a field emission-scanning electron microscopy (FE–SEM), exhibited a film surface area as an effective bio-sensing matrix for enzyme immobilization. The structural characterization and monitoring of the biosensor fabrication was performed using UV–Vis, Fourier Transform Infrared (FT-IR), Raman Spectroscopy, Thermogravimetric Analysis (TGA), Cyclic Voltammetry (CV), and Electrochemical Impedance Spectroscopy (EIS) techniques. The impedimetric results of the FTO/ZnO/Urs biosensor showed a high sensitivity for urea detection within 8.0–110.0 mg dL{sup −1} with the limit of detection as 5.0 mg dL{sup −1}. - Highlights: • Novel disposable impedimetric urea biosensor fabrication based on ZnO–nanoporous transducer • Exploiting omissible PVA polymer as a simple strategy for ZnO–nanoporous film preparation • ZnO–nanoporous film as a good pore framework with large surface area/volume for enzyme immobilization • Application of impedimetric measurement for urea monitoring due to its rapidity, sensitivity, and

  11. Electrochemical and dissolution studies on coated film and magnetite pellet in PDCA and NTA based formulations

    International Nuclear Information System (INIS)

    Srinivasan, M.P.; Sumathi, S.; Rangarajan, S.; Narasimhan, S.V.

    2000-01-01

    In water cooled nuclear reactors magnetite often exists as both mobile particulate protective film on the inner surface of the PHT system. To determine the mechanism and kinetics of dissolution from a film coated on carbon steel (CS) and magnetite pellet electrochemical measurements were carried out in 2,6-pyridine dicarboxylic acid (PDCA) and nitrilo-triacetic acid (NTA) based formulations containing ascorbic acid (AA) and citric acid (CA) at 28 degC and 60 degC. The solution redox potential arises based on the release of relative amounts of Fe 2+ and Fe 3+ . Complexation, adsorption and reduction affect the concentration of these species in solutions. On coated specimen, the pore size and rate of formation via auto reduction contribute to the observed potential. In PDCA based formulation higher percentage of magnetite dissolution with lower base metal corrosion was observed as compared to that in NTA based formulation. The base metal aided dissolution due to the pores and microcracks in the film (Auto reduction) was observed for coated film. The dominant role of surface adsorption characteristics of PDCA, AA and CA were evident in magnetite pellet dissolution studies. (author)

  12. A radiochromic film based on leucomalachite green for high-dose dosimetry applications

    International Nuclear Information System (INIS)

    Soliman, Y.S.; Basfar, A.A.; Msalam, R.I.

    2014-01-01

    A colorless polyvinyl butyral film (PVB) based on radiation-sensitive dye of leucomalachite green (LMG) was investigated as a high-dose dosimeter for gamma radiation processing applications in the dose range of 3–150 kGy. The useful applications for such dose range are food irradiation treatment, medical devices sterilization and polymer modification. Gamma irradiation of the film induces a significant intensity of green color, which can be characterized by a main absorption band at 627 nm and a small band at 425 nm. The variation in response of irradiated film stored in the dark and under laboratory light illumination was less than 3% during the first 6 days of storage. The response of film during irradiation was slightly influenced by relative humidity in the range of 12–76%; however, it was significantly affected by temperature in the range of 5–40 °C. The radiation chemical yield was reported to be 6.76 × 10 −6  mol/J at the absorbed dose of 30 kGy for the film containing 6.5% of LMG dye. The overall uncertainty associated with routine dose monitoring would be less than 6% at a 95% confidence level if the dosimeter was being corrected for irradiation conditions and being calibrated with reference standard dosimeter in the production facility. - Highlights: • Development of a radiochromic film based on leucomalachite green dye for radiation processing dosimetry. • The dosimeter useful dose range is 3–150 kGy. • The dosimeter was slightly influenced by humidity levels during irradiation over the range of 12–76%. • The films stored in the dark have a good shelf life with a good stable response after irradiation. • Overall uncertainty of the dosimeter was less than 4.3% at σ

  13. Development and Characterization of Novel Films Based on Sulfonamide-Chitosan Derivatives for Potential Wound Dressing

    Directory of Open Access Journals (Sweden)

    Oana Maria Dragostin

    2015-12-01

    Full Text Available The objective of this study was to develop new films based on chitosan functionalized with sulfonamide drugs (sulfametoxydiazine, sulfadiazine, sulfadimetho-xine, sulfamethoxazol, sulfamerazine, sulfizoxazol in order to enhance the biological effects of chitosan. The morphology and physical properties of functionalized chitosan films as well the antioxidant effects of sulfonamide-chitosan derivatives were investigated. The chitosan-derivative films showed a rough surface and hydrophilic properties, which are very important features for their use as a wound dressing. The film based on chitosan-sulfisoxazol (CS-S6 showed the highest swelling ratio (197% and the highest biodegradation rate (63.04% in comparison to chitosan film for which the swelling ratio was 190% and biodegradation rate was only 10%. Referring to the antioxidant effects the most active was chitosan-sulfamerazine (CS-S5 which was 8.3 times more active than chitosan related to DPPH (1,1-diphenyl-2-picrylhydrazyl radical scavenging ability. This compound showed also a good ferric reducing power and improved total antioxidant capacity.

  14. The composite phthalocyanine-based Langmuir-Blodgett films: structural peculiarities and NO-sensitive properties

    Energy Technology Data Exchange (ETDEWEB)

    Emelianov, I.L.; Khatko, V.V. [Nat. Acad. of Sci., Minsk (Belarus). Phys. Tech. Inst.

    1999-10-08

    Surface pressure versus area per molecule isotherms of the Langmuir monolayers of copper tetra-tert-butyl phthalocyanine (abbreviated as CuTTBPc), arachidic acid (abbreviated as AA), and their mixtures were measured depending upon the film component ratio and ionic content of the subphase. Substantial deviations of the mixed monolayer behaviour from an ideal one, which is characteristic of fully immiscible compounds forming separate surface domains on the liquid subphase, were observed if the molar fraction of AA in mixed monolayers exceeded 50%. This abnormality in the monolayer behaviour correlated with the drastic changes in the kinetics responses to NO gas of the sensors based on the mixed Langmuir-Blodgett (LB) films. The comparison and analysis of the results obtained suggest that the gas-sensitive properties of the two-component LB films are determined by two features of their structure, namely, hole-like defects existing in the AA matrix and interlayer cavities. The corresponding structure model of the mixed films is proposed. The results obtained may be useful for understanding the gas-sensitive mechanism of the composite phthalocyanine-based LB films. (orig.)

  15. Preparation and performance of Ecobras/bentonite biodegrading films; Preparacao e desempenho de filmes polimericos biodegradaveis a base de Ecobras e bentonita

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Ana Nery M.; Melo, Nadja M.C.; Canedo, Eduardo L.; Carvalho, Laura H., E-mail: laura@dema.ufcg.edu.br [Unidade Academica de Engenharia de Materiais, Universidade Federal de Campina Grande (UAEMa/UFCG) Campina Grande, PB (Brazil); Araujo, Arthur R.A. [Felinto Industria e Comercio Ltda., Campina Grande, PB (Brazil)

    2011-07-01

    Compounds based on the biodegradable polymer Ecobras and bentonite clay in its pristine, sonicated, and organically modified with a quaternary ammonium salt forms were prepared as flat films. Clays and compounds were characterized by x-ray diffraction and scanning electron microscopy. Mechanical properties of the films were determined according to pertinent ASTM standards. Reasonable properties, higher than those of the matrix, were obtained with compounds prepared with purified clays and organoclays, particularly for low clay loading. (author)

  16. A time - zero detector based on thin film plastic scintillator

    International Nuclear Information System (INIS)

    Petrovici, M.; Simion, V.; Pagano, A.; Urso, S.; Geraci, E.

    1998-01-01

    Thin film scintillator used as a fast time-zero detector exhibits some advantages: fast response, small energy loss of transmitted particles, insensitivity to radiation damage, high efficiency and high counting rate capability. In order to increase the efficiency of the light collection, the scintillating plastic foil is housed in a reflecting body having an ellipsoidal geometry. A concave ellipsoidal mirror has the property that the geometrical foci are optically conjugate points and consequently, all optical path lengths from one focus to the other via a single reflection are equal. With the thin scintillator foil situated at one focal point and the PM's photocathode at the other one, an excellent light collection can be obtained. The principle of detector and the main components are presented. For our purposes we constructed the detector in two variants: glass mirror and polished aluminium mirror. The semi-axes of the ellipsoidal profile are: a 49.8 mm, b = 34.2 mm for the glass mirror and a = 35 mm, b = 26.5 mm for the aluminium mirror, respectively. The diameter of the beam access hole on the both mirrors is 12 mm. The detectors are foreseen to be used at 4π detecting system CHIMERA for experiments with heavy ion beams at intermediate energies delivered by Superconducting Cyclotron from LNS - Catania. Presently, the performance of these detectors are tested using alpha radioactive sources and in-beam measurements. (authors)

  17. The influence of thickness on memory characteristic based on nonvolatile tuning behavior in poly(N-vinylcarbazole) films

    International Nuclear Information System (INIS)

    Sun, Yanmei; Ai, Chunpeng; Lu, Junguo; Li, Lei; Wen, Dianzhong; Bai, Xuduo

    2016-01-01

    The memory characteristic based on nonvolatile tuning behavior in indium tin oxide/poly(N-vinylcarbazole)/aluminum (ITO/PVK/Al) was investigated, the different memory behaviors were first observed in PVK film as the film thickness changing. By control of PVK film thickness with different spinning speeds, the nonvolatile behavior of ITO/PVK/Al sandwich structure can be tuned in a controlled manner. Obviously different nonvolatile behaviors, such as (i) flash memory behavior and (ii) write-once-read-many times (WORM) memory behavior are from the current–voltage (I–V) characteristics of the PVK films. The results suggest that the film thickness plays a key part in determining the memory type of the PVK. - Highlights: • The different memory behaviors were observed in PVK film. • The nonvolatile behavior of ITO/PVK/Al sandwich structure can be tuned. • The film thickness plays a key part in determining the memory type of the PVK.

  18. Water-based preparation of spider silk films as drug delivery matrices.

    Science.gov (United States)

    Agostini, Elisa; Winter, Gerhard; Engert, Julia

    2015-09-10

    The main focus of this work was to obtain a drug delivery matrix characterized by biocompatibility, water insolubility and good mechanical properties. Moreover the preparation process has to be compatible with protein encapsulation and the obtained matrix should be able to sustain release a model protein. Spider silk proteins represent exceptional natural polymers due to their mechanical properties in combination with biocompatibility. As both hydrophobic and slowly biodegrading biopolymers, recombinant spider silk proteins fulfill the required properties for a drug delivery system. In this work, we present the preparation of eADF4(C16) films as drug delivery matrices without the use of any organic solvent. Water-based spider silk films were characterized in terms of protein secondary structure, thermal stability, zeta-potential, solubility, mechanical properties, and water absorption and desorption. Additionally, this study includes an evaluation of their application as a drug delivery system for both small molecular weight drugs and high molecular weight molecules such as proteins. Our investigation focused on possible improvements in the film's mechanical properties including plasticizers in the film matrix. Furthermore, different film designs were prepared, such as: monolayer, coated monolayer, multilayer (sandwich), and coated multilayer. The release of the model protein BSA from these new systems was studied. Results indicated that spider silk films are a promising protein drug delivery matrix, capable of releasing the model protein over 90 days with a release profile close to zero order kinetic. Such films could be used for several pharmaceutical and medical purposes, especially when mechanical strength of a drug eluting matrix is of high importance. Copyright © 2015 Elsevier B.V. All rights reserved.

  19. Sensory evaluation of aromatic foods packed in developed starch based films using fuzzy logic

    Directory of Open Access Journals (Sweden)

    Tanima Chowdhury

    2015-04-01

    Full Text Available The last two decades have seen attempts to replace non biodegradable, synthetic food packaging films with alternatives made from biopolymers. The objective of the present work was to evaluate sensory quality of tea leaf and culinary tastemaker powder when sealed in pouches based on starch films.Films were developed from corn starch and a functional polysaccharide (FP from amylose (AM, methylcellulose (MC, and hydroxypropylmethylcellulose (HPMC, using a casting technique. Pouches were stored inside a secondary package (plastic jar under ambient condition for 90 days. Sensory attributes of the stored food samples were evaluated (tea in liquor form and the scores analysed by fuzzy logic. Results were compared with similarly stored foods but using market available poly-pouches as packaging material.For tea and tastemaker in general, the relative importance of the sensory attributes under consideration was assessed as:  aroma (Highly important >taste (Highly important>colour (Highly important > strength (Important for tea, and taste (Highly important>aroma (Highly important>colour (Important>appearance (Important for tastemaker. Among the three films that were developed, the highly important sensory attributes of aroma and taste were maintained as ‘Very good’ when the foods were packed in starch–HPMC/AM film. When the products were packed in market-available poly-pouches they exhibited similar attributes. With the exception of ‘Very good’ maintenance of the colour of tastemaker by the commercial pouch, irrespective of film and food, the colour and strength/appearance were retained in the ‘Good’-‘Satisfactory’ range. The overall sensory score of tea was also maintained as ‘Very good’ in starch-HPMC film.

  20. Poly(vinyl alcohol)-based film potentially suitable for antimicrobial packaging applications.

    Science.gov (United States)

    Musetti, Alessandro; Paderni, Katia; Fabbri, Paola; Pulvirenti, Andrea; Al-Moghazy, Marwa; Fava, Patrizia

    2014-04-01

    This work aimed at developing a thin and water-resistant food-grade poly(vinyl alcohol) (PVOH)-based matrix able to swell when in contact with high moisture content food products without rupturing to release antimicrobial agents onto the food surface. This film was prepared by blending PVOH and 7.20% (wt/wt of PVOH) of poly(ethylene glycol) (PEG) with citric acid as crosslinking agent. The film-forming solution was then casted onto a flat surface and the obtained film was 60 μm in thickness and showed a good transparency (close to T = 100%) in the visible region (400 to 700 nm). After immersion in water for 72 h at room temperature, the crosslinked matrix loses only 19.2% of its original weight (the percentage includes the amount of unreacted crosslinking agent, antimicrobial in itself). Water content, degree of swelling, and crosslinking density of the film prove that the presence of PEG diminishes the hydrophilic behavior of the material. Also the mechanical properties of the wet and dry film were assessed. Alongside this, 2.5% (wt/wt of dry film) of grapefruit seed extract (GSE), an antimicrobial agent, was added to the film-forming solution just before casting and the ability of the plastic matrix to release the additive was then evaluated in vitro against 2 GSE-susceptible microorganisms, Salmonella enteritidis and Listeria innocua. The results indicate that the developed matrix may be a promising food-grade material for the incorporation of active substances. © 2014 Institute of Food Technologists®

  1. Bio-based biodegradable film to replace the standard polyethylene cover for silage conservation.

    Science.gov (United States)

    Borreani, Giorgio; Tabacco, Ernesto

    2015-01-01

    The research was aimed at studying whether the polyethylene (PE) film currently used to cover maize silage could be replaced with bio-based biodegradable films, and at determining the effects on the fermentative and microbiological quality of the resulting silages in laboratory silo conditions. Biodegradable plastic film made in 2 different formulations, MB1 and MB2, was compared with a conventional 120-μm-thick PE film. A whole maize crop was chopped; ensiled in MB1, MB2, and PE plastic bags, 12.5kg of fresh weight per bag; and opened after 170d of conservation. At silo opening, the microbial and fermentative quality of the silage was analyzed in the uppermost layer (0 to 50mm from the surface) and in the whole mass of the silo. All the silages were well fermented with little differences in fermentative quality between the treatments, although differences in the mold count and aerobic stability were observed in trial 1 for the MB1 silage. These results have shown the possibility of successfully developing a biodegradable cover for silage for up to 6mo after ensiling. The MB2 film allowed a good silage quality to be obtained even in the uppermost part of the silage close to the plastic film up to 170d of conservation, with similar results to those obtained with the PE film. The promising results of this experiment indicate that the development of new degradable materials to cover silage till 6mo after ensiling could be possible. Copyright © 2015 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  2. Quadratic Regression-based Non-uniform Response Correction for Radiochromic Film Scanners

    International Nuclear Information System (INIS)

    Jeong, Hae Sun; Kim, Chan Hyeong; Han, Young Yih; Kum, O Yeon

    2009-01-01

    In recent years, several types of radiochromic films have been extensively used for two-dimensional dose measurements such as dosimetry in radiotherapy as well as imaging and radiation protection applications. One of the critical aspects in radiochromic film dosimetry is the accurate readout of the scanner without dose distortion. However, most of charge-coupled device (CCD) scanners used for the optical density readout of the film employ a fluorescent lamp or a coldcathode lamp as a light source, which leads to a significant amount of light scattering on the active layer of the film. Due to the effect of the light scattering, dose distortions are produced with non-uniform responses, although the dose is uniformly irradiated to the film. In order to correct the distorted doses, a method based on correction factors (CF) has been reported and used. However, the prediction of the real incident doses is difficult when the indiscreet doses are delivered to the film, since the dose correction with the CF-based method is restrictively used in case that the incident doses are already known. In a previous study, therefore, a pixel-based algorithm with linear regression was developed to correct the dose distortion of a flatbed scanner, and to estimate the initial doses. The result, however, was not very good for some cases especially when the incident dose is under approximately 100 cGy. In the present study, the problem was addressed by replacing the linear regression with the quadratic regression. The corrected doses using this method were also compared with the results of other conventional methods

  3. Film-based X-ray tomography combined with digital image processing: investigation of an ancient pattern-welded sword

    International Nuclear Information System (INIS)

    Lindegaard-Andersen, A.; Vedel, T.; Jeppesen, L.; Gottlieb, B.

    1988-01-01

    Film-based X-ray tomography and digital image processing have been used to investigate an inhomogeneous object of non-circular cross-section. The feasibility of using digital image processing to compensate for the poor contrast resolution inherent in film-based tomography has been demonstrated. (author)

  4. Effect of chromium and phosphorus on the physical properties of iron and titanium-based amorphous metallic alloy films

    Science.gov (United States)

    Distefano, S.; Rameshan, R.; Fitzgerald, D. J.

    1991-01-01

    Amorphous iron and titanium-based alloys containing various amounts of chromium, phosphorus, and boron exhibit high corrosion resistance. Some physical properties of Fe and Ti-based metallic alloy films deposited on a glass substrate by a dc-magnetron sputtering technique are reported. The films were characterized using differential scanning calorimetry, stress analysis, SEM, XRD, SIMS, electron microprobe, and potentiodynamic polarization techniques.

  5. Quadruple-Junction Thin-Film Silicon-Based Solar Cells

    NARCIS (Netherlands)

    Si, F.T.

    2017-01-01

    The direct utilization of sunlight is a critical energy source in a sustainable future. One of the options is to convert the solar energy into electricity using thin-film silicon-based solar cells (TFSSCs). Solar cells in a triple-junction configuration have exhibited the highest energy conversion

  6. Magnetic properties of thin Ni films measured by a dc SQUID-based magnetic microscope

    DEFF Research Database (Denmark)

    Snigirev, O.V.; Andreev, K.E.; Tishin, A.M.

    1997-01-01

    We have applied a scanning HTS (high-temperature superconductor) de SQUID (superconducting quantum interference device) -based magnetic microscope to study the magnetic properties of Au/Ni/Si(100) films in the thickness range from 8 to 200 Angstrom at T = 77 K. A one-domain structure with in...

  7. Energy efficiency of a photovoltaic cell based thin films CZTS by ...

    African Journals Online (AJOL)

    Energy efficiency of a photovoltaic cell based thin films CZTS by SCAPS. ... use of natural resources, the use of renewable energy including solar photovoltaic ... η for typical structures of ZnO / i- ZnO / CdS / CZTS and ITO / ZnO / CdS / CZTS.

  8. Magnetic properties of FeNi-based thin film materials with different additives

    KAUST Repository

    Liang, C.; Gooneratne, C.P.; Wang, Q.X.; Liu, Y.; Gianchandani, Y.; Kosel, Jü rgen

    2014-01-01

    This paper presents a study of FeNi-based thin film materials deposited with Mo, Al and B using a co-sputtering process. The existence of soft magnetic properties in combination with strong magneto-mechanical coupling makes these materials

  9. Homogeneity Analysis of a MEMS-based PZT Thick Film Vibration Energy Harvester Manufacturing Process

    DEFF Research Database (Denmark)

    Lei, Anders; Xu, Ruichao; Borregaard, Louise M.

    2012-01-01

    This paper presents a homogeneity analysis of a high yield wafer scale fabrication of MEMS-based unimorph silicon/PZT thick film vibration energy harvesters aimed towards vibration sources with peak vibrations in the range of around 300Hz. A wafer with a yield of 91% (41/45 devices) has been...

  10. A cubic boron nitride film-based fluorescent sensor for detecting Hg2+

    Science.gov (United States)

    Liu, W. M.; Zhao, W. W.; Zhang, H. Y.; Wang, P. F.; Chong, Y. M.; Ye, Q.; Zou, Y. S.; Zhang, W. J.; Zapien, J. A.; Bello, I.; Lee, S. T.

    2009-05-01

    Cubic boron nitride (cBN) film-based sensors for detecting Hg2+ ions were developed by surface functionalization with dansyl chloride. To immobilize dansyl chloride, 3-aminopropyltriethoxy silane was modified on hydroxylated cBN surfaces to form an amino-group-terminated self-assembled monolayer. The covalent attachment of the amino groups was confirmed by x-ray photoelectron spectroscopy. The selectivity and sensitivity of the sensors to detect diverse metal cations in ethanol solutions were studied by using fluorescence spectroscopy, revealing a great selectivity to Hg2+ ions. Significantly, the dansyl-chloride-functionalized cBN film sensors were recyclable after the sensing test.

  11. Characterization of tellurium-based films for NO{sub 2} detection

    Energy Technology Data Exchange (ETDEWEB)

    Tsiulyanu, D. [Technical University, Department of Physics, bul. Dacia 41, MD-2060 Kishinau (Moldova, Republic of)]. E-mail: tsiu@cni.md; Tsiulyanu, A. [Technical University, Department of Physics, bul. Dacia 41, MD-2060 Kishinau (Moldova, Republic of); Liess, H.-D. [University of the Bundeswehr Munich, Faculty of Electrical Engineering and Information Technology, Institute of Physics, D-85577 Neubiberg (Germany); Eisele, I. [University of the Bundeswehr Munich, Faculty of Electrical Engineering and Information Technology, Institute of Physics, D-85577 Neubiberg (Germany)

    2005-08-01

    Sensing characteristics of tellurium-based thin films for NO{sub 2} monitoring was studied systematically. The influence of contact materials, thermal treatment, temperature and thickness of the samples on the electrical conductivity and sensitivity to NO{sub 2} with respect to scanning electron microscopy analyses is given. The possibility is shown to optimize the properties of the films for the development of a simple and stable NO{sub 2} sensor device with rapid response/recovery time and low operating temperature. The sensing mechanism is discussed for the direct interaction of gaseous species with lone-pair electrons of chalcogen atoms.

  12. Optimized electrode coverage of membrane actuators based on epitaxial PZT thin films

    International Nuclear Information System (INIS)

    Nguyen, M D; Dekkers, M; Blank, D H A; Rijnders, G; Nazeer, H

    2013-01-01

    This research presents an optimization of piezoelectric membrane actuators by maximizing the actuator displacement. Membrane actuators based on epitaxial Pb(Zr,Ti)O 3 thin films grown on all-oxide electrodes and buffer layers using silicon technology were fabricated. Electrode coverage was found to be an important factor in the actuation displacement of the piezoelectric membranes. The optimum electrode coverage for maximum displacement was theoretically determined to be 39%, which is in good agreement with the experimental results. Dependences of membrane displacement and optimum electrode coverage on membrane diameter and PZT-film/Si-device-layer thickness ratio have also been investigated. (paper)

  13. Mechanical Properties of Oxide Films on Electrolytic In-process Dressing (ELID) Copper-based Grinding Wheel

    Science.gov (United States)

    Kuai, J. C.; Wang, J. W.; Jiang, C. R.; Zhang, H. L.; Yang, Z. B.

    2018-05-01

    The mechanical properties of oxide films on copper based grinding wheel were studied by nanoindentation technique. The analysis of load displacement shows that the creep phenomenon occurs during the loading stage. Results show that the oxide film and the matrix have different characteristics, and the rigidity of the copper based grinding wheel is 0.6-1.3mN/nm, which is weaker than that of the matrix; the hardness of the oxide film is 2000-2300MPa, which is higher than the matrix; and the elastic modulus of the oxide film is 100-120GPa, also higher than the matrix.

  14. Enhanced properties of UPE/ESOA partially bio-nanocomposites ...

    Indian Academy of Sciences (India)

    59

    Epoxidized Soybean Oil Acrylate (ESOA) to recuperate its performance. .... Tensile properties were evaluated by using the universal testing machine (Model 3369) in .... carboxyl band at 1670cm-1 which are essential for making reaction with ..... increased hours of NaCl treatment, very small weight was gained in all the ...

  15. Development of silver and clay-starch bio-nanocomposites

    OpenAIRE

    Abreu, Ana S.; Oliveira, M.; Machado, A. V.

    2014-01-01

    Starch, among biopolymers is that had the lowest production cost, wide availability, fully biodegradability and is a renewable agriculture resource. Starch due to its sensitivity to humidity and poor mechanical properties cannot be used in many applications. For that, the dispersion of clays in this material improves their physical and mechanical properties, at very low filler loadings. On the other hand, the incorporation of silver nanoparticles into biocompatible and biod...

  16. Preparation and physicochemistry properties of smart edible films based on gelatin-starch nanoparticles.

    Science.gov (United States)

    Tao, Furong; Shi, Chengmei; Cui, Yuezhi

    2018-04-24

    Among the natural polymers able to form edible films, starch and gelatin (Gel) are potential sources. Corn starch is a polysaccharide widely produced around the world, and gelatin differs from other hydrocolloids as a fully digestible protein, containing nearly all the essential amino acids, except tryptophan. Based on this, with advantages such as abundance, relatively low cost, biodegradability, and edibility, studies considering alternative systems for food protection that utilize biopolymers have increased significantly in the recent years. A novel macromolecular crosslinker Starch-BTCAD-NHS (starch - butanetetracarboxylic acid dianhydride - N-hydroxysuccinimide, SBN) was successfully prepared to modify gelatin film. Compared with the blank gelatin films, the resulting SBN-Gel films exhibited the improved surface hydrophobicity, the higher tense strength and elongation-at-break, the lower Young's modulus values, the greater opacity, the poorer water vapor uptake properties and better anti-degradation capacity. The modified gelatin film material with advanced properties obtained in this work was safe, stable eco-friendly and biorefractory, and was an ideal choice to form a packaging in food industry. Also, the crosslinking SBN-gelatin coating was effective in reducing the corruption and extending the shelf life for the peeled apple substantially. This article is protected by copyright. All rights reserved.

  17. InGaN-based thin film solar cells: Epitaxy, structural design, and photovoltaic properties

    Energy Technology Data Exchange (ETDEWEB)

    Sang, Liwen, E-mail: SANG.Liwen@nims.go.jp [International Center for Material Nanoarchitectonics (MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); JST-PRESTO, The Japan Science and Technology Agency, Tokyo 102-0076 (Japan); Liao, Meiyong; Koide, Yasuo [Wide Bandgap Materials Group, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Sumiya, Masatomo [Wide Bandgap Materials Group, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); JST-ALCA, The Japan Science and Technology Agency, Tokyo 102-0076 (Japan)

    2015-03-14

    In{sub x}Ga{sub 1−x}N, with the tunable direct bandgaps from ultraviolet to near infrared region, offers a promising candidate for the high-efficiency next-generation thin-film photovoltaic applications. Although the adoption of thick InGaN film as the active region is desirable to obtain efficient light absorption and carrier collection compared to InGaN/GaN quantum wells structure, the understanding on the effect from structural design is still unclear due to the poor-quality InGaN films with thickness and difficulty of p-type doping. In this paper, we comprehensively investigate the effects from film epitaxy, doping, and device structural design on the performances of the InGaN-based solar cells. The high-quality InGaN thick film is obtained on AlN/sapphire template, and p-In{sub 0.08}Ga{sub 0.92}N is achieved with a high hole concentration of more than 10{sup 18 }cm{sup −3}. The dependence of the photovoltaic performances on different structures, such as active regions and p-type regions is analyzed with respect to the carrier transport mechanism in the dark and under illumination. The strategy of improving the p-i interface by using a super-thin AlN interlayer is provided, which successfully enhances the performance of the solar cells.

  18. InGaN-based thin film solar cells: Epitaxy, structural design, and photovoltaic properties

    Science.gov (United States)

    Sang, Liwen; Liao, Meiyong; Koide, Yasuo; Sumiya, Masatomo

    2015-03-01

    InxGa1-xN, with the tunable direct bandgaps from ultraviolet to near infrared region, offers a promising candidate for the high-efficiency next-generation thin-film photovoltaic applications. Although the adoption of thick InGaN film as the active region is desirable to obtain efficient light absorption and carrier collection compared to InGaN/GaN quantum wells structure, the understanding on the effect from structural design is still unclear due to the poor-quality InGaN films with thickness and difficulty of p-type doping. In this paper, we comprehensively investigate the effects from film epitaxy, doping, and device structural design on the performances of the InGaN-based solar cells. The high-quality InGaN thick film is obtained on AlN/sapphire template, and p-In0.08Ga0.92N is achieved with a high hole concentration of more than 1018 cm-3. The dependence of the photovoltaic performances on different structures, such as active regions and p-type regions is analyzed with respect to the carrier transport mechanism in the dark and under illumination. The strategy of improving the p-i interface by using a super-thin AlN interlayer is provided, which successfully enhances the performance of the solar cells.

  19. Piezoelectric actuated micro-resonators based on the growth of diamond on aluminum nitride thin films

    International Nuclear Information System (INIS)

    Hees, J; Heidrich, N; Pletschen, W; Sah, R E; Wolfer, M; Lebedev, V; Nebel, C E; Ambacher, O; Williams, O A

    2013-01-01

    Unimorph heterostructures based on piezoelectric aluminum nitride (AlN) and diamond thin films are highly desirable for applications in micro- and nanoelectromechanical systems. In this paper, we present a new approach to combine thin conductive boron-doped as well as insulating nanocrystalline diamond (NCD) with sputtered AlN films without the need for any buffer layers between AlN and NCD or polishing steps. The zeta potentials of differently treated nanodiamond (ND) particles in aqueous colloids are adjusted to the zeta potential of AlN in water. Thereby, the nucleation density for the initial growth of diamond on AlN can be varied from very low (10 8 cm −2 ), in the case of hydrogen-treated ND seeding particles, to very high values of 10 11 cm −2 for oxidized ND particles. Our approach yielding high nucleation densities allows the growth of very thin NCD films on AlN with thicknesses as low as 40 nm for applications such as microelectromechanical beam resonators. Fabricated piezo-actuated micro-resonators exhibit enhanced mechanical properties due to the incorporation of boron-doped NCD films. Highly boron-doped NCD thin films which replace the metal top electrode offer Young’s moduli of more than 1000 GPa. (paper)

  20. Optical and structural characterization of nickel oxide-based thin films obtained by chemical bath deposition

    International Nuclear Information System (INIS)

    Vidales-Hurtado, M.A.; Mendoza-Galvan, A.

    2008-01-01

    Nickel oxide-based thin films were obtained using the chemical bath deposition method on glass and silicon substrates. The precursor solution used was a mixture of nickel nitrate, urea, and deionized water. Molar concentration of nickel (0.3-1.0 M), deposition time, and immersing cycles were considered as deposition variables. Infrared spectroscopy and X-ray diffraction data reveal that all as-deposited films correspond to the transparent turbostratic phase α(II)-Ni(OH) 2 . However, the rate of deposition depends on nickel content in the solution. After annealing in air at temperatures above of 300 deg. C, the films are transformed to the NiO phase and show a grey/black color. In these films, scanning electron microscopy images show aggregates of thin stacked sheets on their surface, such aggregates can be easily removed leaving only a thin NiO layer of about 30 nm adhered firmly to the substrate, regardless of nickel concentration in the solution and deposition time. In order to obtain thicker NiO films with good optical properties a procedure is developed performing several immersing-annealing cycles

  1. Nanotribological Behavior of Carbon Based Thin Films: Friction and Lubricity Mechanisms at the Nanoscale

    Directory of Open Access Journals (Sweden)

    Costas A. Charitidis

    2013-04-01

    Full Text Available The use of materials with very attractive friction and wear properties has raised much attention in research and industrial sectors. A wide range of tribological applications, including rolling and sliding bearings, machining, mechanical seals, biomedical implants and microelectromechanical systems (MEMS, require thin films with high mechanical strength, chemical inertness, broad optical transparency, high refractive index, wide bandgap excellent thermal conductivity and extremely low thermal expansion. Carbon based thin films like diamond, diamond-like carbon, carbon nitride and cubic boron nitride known as “super-hard” material have been studied thoroughly as the ideal candidate for tribological applications. In this study, the results of experimental and simulation works on the nanotribological behavior of carbon films and fundamental mechanisms of friction and lubricity at the nano-scale are reviewed. The study is focused on the nanomechanical properties and analysis of the nanoscratching processes at low loads to obtain quantitative analysis, the comparison obtain quantitative analysis, the comparison of their elastic/plastic deformation response, and nanotribological behavior of the a-C, ta-C, a-C:H, CNx, and a-C:M films. For ta-C and a-C:M films new data are presented and discussed.

  2. Fabrication of semi-transparent superoleophobic thin film from fabrics and nanoparticle-based hierarchical structure

    Directory of Open Access Journals (Sweden)

    Nishizawa S.

    2013-08-01

    Full Text Available Superoleophobic thin films have many potential applications including fluid transfer, fluid power systems, stain resistant and antifouling materials, and microfluidics among others. Transparency is also desired with superhydrophobicity for their numerous applications; however transparency and oleophobicity are almost incompatible relationship with each other in the point of surface structure. Because oleophobicity required rougher structure at nano-micro scale than hydrophobicity, and these rough structure brings light scattering. So far, there is very few report of the compatible of transparency and superoleophobicity. In this report, we proposed the see-through type fabrics using the nanoparticle-based hierarchical structure thin film for improving both of oleophobicity and transparency. The vacant space between fibrils of fabrics has two important roles: the one is to through the light, another one is to introduce air layer to realize Cassie state of liquid droplet on thin film. To realize the low surface energy and nanoscale rough structure surface on fibrils, we used the spray method with perfluoroalkyl methacrylic copolymer (PMC, silica nano particles and volatile solvent. From the SEM image, the hierarchical structures of nanoparticle were formed uniformly on the fabrics. The transparency of thin film obtained was approximately 61% and the change of transparency between pre-coated fabrics and coated was 11%. From investigation of the surface wettability, the contact angles of oils (rapeseed oil and hexadecane and water droplet on the fabricated film were over 150 degree.

  3. Enzymatic logic calculation systems based on solid-state electrochemiluminescence and molecularly imprinted polymer film electrodes.

    Science.gov (United States)

    Lian, Wenjing; Liang, Jiying; Shen, Li; Jin, Yue; Liu, Hongyun

    2018-02-15

    The molecularly imprinted polymer (MIP) films were electropolymerized on the surface of Au electrodes with luminol and pyrrole (PY) as the two monomers and ampicillin (AM) as the template molecule. The electrochemiluminescence (ECL) intensity peak of polyluminol (PL) of the AM-free MIP films at 0.7V vs Ag/AgCl could be greatly enhanced by AM rebinding. In addition, the ECL signals of the MIP films could also be enhanced by the addition of glucose oxidase (GOD)/glucose and/or ferrocenedicarboxylic acid (Fc(COOH) 2 ) in the testing solution. Moreover, Fc(COOH) 2 exhibited cyclic voltammetric (CV) response at the AM-free MIP film electrodes. Based on these results, a binary 3-input/6-output biomolecular logic gate system was established with AM, GOD and Fc(COOH) 2 as inputs and the ECL responses at different levels and CV signal as outputs. Some functional non-Boolean logic devices such as an encoder, a decoder and a demultiplexer were also constructed on the same platform. Particularly, on the basis of the same system, a ternary AND logic gate was established. The present work combined MIP film electrodes, the solid-state ECL, and the enzymatic reaction together, and various types of biomolecular logic circuits and devices were developed, which opened a novel avenue to construct more complicated bio-logic gate systems. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Biodegradable multilayer barrier films based on alginate/polyethyleneimine and biaxially oriented poly(lactic acid).

    Science.gov (United States)

    Gu, Chun-Hong; Wang, Jia-Jun; Yu, Yang; Sun, Hui; Shuai, Ning; Wei, Bing

    2013-02-15

    A layer-by-layer (LBL) approach was used to assemble alternating layers of sodium alginate (ALG)/polyethyleneimine (PEI) on biaxially oriented poly(lactic acid) (BOPLA) films in order to produce bio-based all-polymer thin films with low gas permeability. Increasing the depositing of ALG and PEI from 0 to 30 layers results in large thickness variations (from 0 to 3.92 μm). After 30 ALG/PEI layers are deposited, the resulting assembly has an OTR of 1.22 cm(3)/(m(2) day atm). When multiplied by thickness, the resulting oxygen permeability (OP) is found to be less than 3.8×10(-17) cm(3) cm/cm(2) s Pa, which is almost 3 orders of magnitude lower than that of uncoated BOPLA film (1.8×10(-14) cm(3)cm/cm(2) s Pa). At the same time, the resulting multilayer-coated BOPLA films maintain high optical clarity and tensile properties. This unique barrier thin film has become a promising alternative to non-biodegradable synthetic food packaging materials. Copyright © 2012 Elsevier Ltd. All rights reserved.

  5. Ultra thin hydro-films based on lactose-crosslinked fish gelatin for wound healing applications.

    Science.gov (United States)

    Etxabide, Alaitz; Vairo, Claudia; Santos-Vizcaino, Edorta; Guerrero, Pedro; Pedraz, Jose Luis; Igartua, Manoli; de la Caba, Koro; Hernandez, Rosa Maria

    2017-09-15

    This study focuses on the development and characterization of an ultra thin hydro-film based on lactose-mediated crosslinking of fish gelatin by Maillard reaction. Lactose results in the only efficient crosslinker able to produce resistant to handling hydro-films when compared to conventional crosslinkers such as glutaraldehyde or genipin (tested at 25 and 37°C in phosphate buffer saline solution (PBS)).The disappearance of the peak related to the N-containing groups (XPS) and the images obtained by SEM and AFM demonstrate the highly ordered nano-scaled structure of lactose-crosslinked gelatin, confirming the crosslinking efficiency. This dressing presents high hydrophilicity and mild occlusivity, as shown by the swelling curve (max swelling at 5min) and by the occlusion factor of 25.17±0.99%, respectively. It demonstrates high stability to hydrolysis or cell-mediated degradation. Moreover, ISO 10993-5:2009 biocompatibility assay results in undetectable cytotoxicity effects. Spreading, adhesion and proliferation assays confirm the excellent adaptability of the cells onto the hydro-film surface without invading the dressing. Finally, the hydro-film enables the controlled delivery of therapeutic factors, such as the epidermal growth factor (EGF). This study demonstrates that lactose-mediated crosslinking is able to produce ultra thin gelatin hydro-films with suitable properties for biomedical applications, such as wound healing. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Ceramic thick film humidity sensor based on MgTiO3 + LiF

    International Nuclear Information System (INIS)

    Kassas, Ahmad; Bernard, Jérôme; Lelièvre, Céline; Besq, Anthony; Guhel, Yannick; Houivet, David; Boudart, Bertrand; Lakiss, Hassan; Hamieh, Tayssir

    2013-01-01

    Graphical abstract: - Highlights: • The fabricated sensor based on MgTiO 3 + LiF materials used the spin coating technology. • The response time is 70 s to detect variation between 5 and 95% relative humidity. • The addition of Scleroglucan controls the viscosity and decreases the roughness of thick film surface. • This humidity sensor is a promising, low-cost, high-quality, reliable ceramic films, that is highly sensitive to humidity. - Abstract: The feasibility of humidity sensor, consisting of a thick layer of MgTiO 3 /LiF materials on alumina substrate, was studied. The thermal analysis TGA-DTGA and dilatometric analysis worked out to confirm the sintering temperature. An experimental plan was applied to describe the effects of different parameters in the development of the thick film sensor. Structural and microstructural characterizations of the developed thick film were made. Rheological study with different amounts of a thickener (scleroglucan “sclg”), showing the behavior variation, as a function of sclg weight % was illustrated and rapprochement with the results of thickness variation as a function of angular velocity applied in the spin coater. The electrical and dielectric measurements confirmed the sensitivity of the elaborated thick film against moisture, along with low response time

  7. Analysis of micro vibration in gas film of aerostatic guide way based on molecule collision theory

    Directory of Open Access Journals (Sweden)

    Yang Shao Hua

    2016-01-01

    Full Text Available Micro vibration of the aerostatic guide way has a significant impact on its dynamic characteristics and stability, which limits the development of pneumatic component. High pressure gas molecules have been collided with the supporting surface and the internal surface of the throttle during the flow process. Variable impulse of the surfaces aside for the gas film are affected by the changes of impulse which formed irregular impact force in horizontal and vertical direction. Micro-vibration takes place based on the natural frequency of the system and its frequency doubling. In this paper, the vibration model was established to describe the dynamic characteristics of the gas film, and the formation mechanism of micro vibration in the film is defined. Through the simulation analysis and experimental comparison, formation mechanism of the micro vibration in the gas film is confirmed. It was proposed that the micro vibration of gas film can be produced no matter whether there is a gas chamber or not in the throttle. Under the same conditions, the micro vibration of the guide way with air chamber is greater than that without any chamber. The frequency points of the vibration peaks are almost the same, as well as the vibration pattern in the frequency domain.

  8. Ceramic thick film humidity sensor based on MgTiO{sub 3} + LiF

    Energy Technology Data Exchange (ETDEWEB)

    Kassas, Ahmad, E-mail: a.kassas.mcema@ul.edu.lb [Faculty of Agricultural Engineering and Veterinary Medicine, Laboratory of Materials, Catalysis, Environment and Analytical Methods (MCEMA), Faculty of Sciences and Doctoral School of Sciences and Technology (EDST), Lebanese University, Hariri Campus, Hadath, Beirut (Lebanon); Laboratoire Universitaire des Sciences Appliquées de Cherbourg (LUSAC), 50130 Cherbourg-Octeville (France); Bernard, Jérôme; Lelièvre, Céline; Besq, Anthony; Guhel, Yannick; Houivet, David; Boudart, Bertrand [Laboratoire Universitaire des Sciences Appliquées de Cherbourg (LUSAC), 50130 Cherbourg-Octeville (France); Lakiss, Hassan [Faculty of Agricultural Engineering and Veterinary Medicine, Laboratory of Materials, Catalysis, Environment and Analytical Methods (MCEMA), Faculty of Sciences and Doctoral School of Sciences and Technology (EDST), Lebanese University, Hariri Campus, Hadath, Beirut (Lebanon); Faculty of Engineering, Section III, Hariri Campus, Hadath, Beirut (Lebanon); Hamieh, Tayssir [Faculty of Agricultural Engineering and Veterinary Medicine, Laboratory of Materials, Catalysis, Environment and Analytical Methods (MCEMA), Faculty of Sciences and Doctoral School of Sciences and Technology (EDST), Lebanese University, Hariri Campus, Hadath, Beirut (Lebanon)

    2013-10-15

    Graphical abstract: - Highlights: • The fabricated sensor based on MgTiO{sub 3} + LiF materials used the spin coating technology. • The response time is 70 s to detect variation between 5 and 95% relative humidity. • The addition of Scleroglucan controls the viscosity and decreases the roughness of thick film surface. • This humidity sensor is a promising, low-cost, high-quality, reliable ceramic films, that is highly sensitive to humidity. - Abstract: The feasibility of humidity sensor, consisting of a thick layer of MgTiO{sub 3}/LiF materials on alumina substrate, was studied. The thermal analysis TGA-DTGA and dilatometric analysis worked out to confirm the sintering temperature. An experimental plan was applied to describe the effects of different parameters in the development of the thick film sensor. Structural and microstructural characterizations of the developed thick film were made. Rheological study with different amounts of a thickener (scleroglucan “sclg”), showing the behavior variation, as a function of sclg weight % was illustrated and rapprochement with the results of thickness variation as a function of angular velocity applied in the spin coater. The electrical and dielectric measurements confirmed the sensitivity of the elaborated thick film against moisture, along with low response time.

  9. Properties and Applications of High Emissivity Composite Films Based on Far-Infrared Ceramic Powder.

    Science.gov (United States)

    Xiong, Yabo; Huang, Shaoyun; Wang, Wenqi; Liu, Xinghai; Li, Houbin

    2017-11-29

    Polymer matrix composite materials that can emit radiation in the far-infrared region of the spectrum are receiving increasing attention due to their ability to significantly influence biological processes. This study reports on the far-infrared emissivity property of composite films based on far-infrared ceramic powder. X-ray fluorescence spectrometry, Fourier transform infrared spectroscopy, thermogravimetric analysis, and X-ray powder diffractometry were used to evaluate the physical properties of the ceramic powder. The ceramic powder was found to be rich in aluminum oxide, titanium oxide, and silicon oxide, which demonstrate high far-infrared emissivity. In addition, the micromorphology, mechanical performance, dynamic mechanical properties, and far-infrared emissivity of the composite were analyzed to evaluate their suitability for strawberry storage. The mechanical properties of the far-infrared radiation ceramic (cFIR) composite films were not significantly influenced ( p ≥ 0.05) by the addition of the ceramic powder. However, the dynamic mechanical analysis (DMA) properties of the cFIR composite films, including a reduction in damping and shock absorption performance, were significant influenced by the addition of the ceramic powder. Moreover, the cFIR composite films showed high far-infrared emissivity, which has the capability of prolonging the storage life of strawberries. This research demonstrates that cFIR composite films are promising for future applications.

  10. Characterization of Chemical Vapor Deposited Tetraethyl Orthosilicate based SiO2 Films for Photonic Devices

    Directory of Open Access Journals (Sweden)

    Jhansirani KOTCHARLAKOTA

    2016-05-01

    Full Text Available Silicon has been the choice for photonics technology because of its cost, compatibility with mass production and availability. Silicon based photonic devices are very significant from commercial point of view and are much compatible with established technology. This paper deals with deposition and characterization of SiO2 films prepared by indigenously developed chemical vapor deposition system. Ellipsometry study of prepared films showed an increase in refractive index and film thickness with the increment in deposition temperature. The deposition temperature has a significant role for stoichiometric SiO2 films, FTIR measurement has shown the three characteristics peaks of Si-O-Si through three samples prepared at temperatures 700, 750 and 800 °C while Si-O-Si stretching peak positions were observed to be shifted to lower wavenumber in accordance to the temperature. FESEM analysis has confirmed the smooth surface without any crack or disorder while EDX analysis showed the corresponding peaks of compositional SiO2 films.DOI: http://dx.doi.org/10.5755/j01.ms.22.1.7245

  11. Partial characterization of chayotextle starch-based films added with ascorbic acid encapsulated in resistant starch.

    Science.gov (United States)

    Martínez-Ortiz, Miguel A; Vargas-Torres, Apolonio; Román-Gutiérrez, Alma D; Chavarría-Hernández, Norberto; Zamudio-Flores, Paul B; Meza-Nieto, Martín; Palma-Rodríguez, Heidi M

    2017-05-01

    Chayotextle starch was modified by subjecting it to a dual treatment with acid and heating-cooling cycles. This caused a decrease in the content of amylose, which showed values of 30.22%, 4.80%, 3.27% and 3.57% for native chayotextle starch (NCS), starch modified by acid hydrolysis (CMS), and CMS with one (CMS1AC) and three autoclave cycles (CMS3AC), respectively. The percentage of crystallinity showed an increase of 36.9%-62% for NCS and CMS3AC. The highest content of resistant starch (RS) was observed in CMS3AC (37.05%). The microcapsules were made with CMS3AC due to its higher RS content; the total content of ascorbic acid of the microcapsules was 82.3%. The addition of different concentrations of CMS3AC microcapsules (0%, 2.5%, 6.255% and 12.5%) to chayotextle starch-based films (CSF) increased their tensile strength and elastic modulus. The content of ascorbic acid and RS in CSF was ranged from 0% to 59.4% and from 4.84% to 37.05% in the control film and in the film mixed with CMS3AC microcapsules, respectively. Water vapor permeability (WVP) values decreased with increasing concentrations of microcapsules in the films. Microscopy observations showed that higher concentrations of microcapsules caused agglomerations due their poor distribution in the matrix of the films. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Verification of the IVA4 film boiling model with the data base of Liu and Theofanous

    Energy Technology Data Exchange (ETDEWEB)

    Kolev, N.I. [Siemens AG Unternehmensbereich KWU, Erlangen (Germany)

    1998-01-01

    Part 1 of this work presents a closed analytical solution for mixed-convection film boiling on vertical walls. Heat transfer coefficients predicted by the proposed model and experimental data obtained at the Royal Institute of Technology in Sweden by Okkonen et al are compared. All data predicted are inside the {+-}10% error band, with mean averaged error being below 4% using the slightly modified analytical solution. The solution obtained is recommended for practical applications. The method presented here is used in Part 2 as a guideline for developing model for film boiling on spheres. The new semi-empirical film boiling model for spheres used in IVA4 computer code is compared with the experimental data base obtained by Liu and Theofanous. The data are predicted within {+-}30% error band. (author)

  13. Superconducting Mercury-Based Cuprate Films with a Zero-Resistance Transition Temperature of 124 Kelvin

    Science.gov (United States)

    Tsuei, C. C.; Gupta, A.; Trafas, G.; Mitzi, D.

    1994-03-01

    The synthesis of high-quality films of the recently discovered mercury-based cuprate films with high transition temperatures has been plagued by problems such as the air sensitivity of the cuprate precursor and the volatility of Hg and HgO. These processing difficulties have been circumvented by a technique of atomic-scale mixing of the HgO and cuprate precursors, use of a protective cap layer, and annealing in an appropriate Hg and O_2 environment. With this procedure, a zero-resistance transition temperature as high as 124 kelvin in c axis-oriented epitaxial HgBa_2CaCu_2O6+δ films has been achieved.

  14. Superconducting mercury-based cuprate films with a zero-resistance transition temperature of 124 Kelvin.

    Science.gov (United States)

    Tsuei, C C; Gupta, A; Trafas, G; Mitzi, D

    1994-03-04

    The synthesis of high-quality films of the recently discovered mercury-based cuprate films with high transition temperatures has been plagued by problems such as the air sensitivity of the cuprate precursor and the volatility of Hg and HgO. These processing difficulties have been circumvented by a technique of atomic-scale mixing of the HgO and cuprate precursors, use of a protective cap layer, and annealing in an appropriate Hg and O(2) environment. With this procedure, a zero-resistance transition temperature as high as 124 kelvin in c axis-oriented epitaxial HgBa(2)CaCu(2)O(6+delta) films has been achieved.

  15. Bionanocomposite films based on plasticized PLA-PHB/cellulose nanocrystal blends.

    Science.gov (United States)

    Arrieta, M P; Fortunati, E; Dominici, F; López, J; Kenny, J M

    2015-05-05

    Optically transparent plasticized poly(lactic acid) (PLA) based bionanocomposite films intended for food packaging were prepared by melt blending. Materials were plasticized with 15wt% of acetyl(tributyl citrate) (ATBC) to improve the material processability and to obtain flexibile films. Poly(hydroxybutyrate) (PHB) was used to increase PLA crystallinity. The thermal stability of the PLA-PHB blends was improved by the addition of 5 wt% of cellulose nanocrystals (CNC) or modified cellulose nanocrystals (CNCs) synthesized from microcrystalline cellulose. The combination of ATBC and cellulose nanocrystals, mainly the better dispersed CNCs, improved the interaction between PLA and PHB. Thus, an improvement on the oxygen barrier and stretchability was achieved in PLA-PHB-CNCs-ATBC which also displayed somewhat UV light blocking effect. All bionanocomposite films presented appropriate disintegration in compost suggesting their possible applications as biodegradable packaging materials. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Thermo-emf of cermet films based on rare earth borides

    International Nuclear Information System (INIS)

    Islamgaliev, R.K.; Zyrin, A.V.; Shulishova, O.I.; Shcherbak, I.A

    1987-01-01

    Thermo-emf and electric conductivity of granulated films which contain a solid solution of europium and praseodymium borides Eu 0.5 Pr 0.5 B 6 as a conducting phase, and glass-crystal binder on the base of alummomagnesial fluosilicates as a dielectric phase are studied within the temperature range of 100-1100 K. Thermo-emf of films has a negative sign within the temperature range of 100-500 K and does not exceed 5 μkV/K according to the absolute value which is close to the value of the conducting phase thermo-emf. A negative sign and a small value of thermo-emf are indicative of the charge transfer in granulated films by electrons. Contribution of each of the components into the general thermo-emf is different at high temperatures in different temperature ranges and depends on the individual physico-chemical properties of the used materials

  17. Third generation biosensing matrix based on Fe-implanted ZnO thin film

    International Nuclear Information System (INIS)

    Saha, Shibu; Gupta, Vinay; Sreenivas, K.; Tan, H. H.; Jagadish, C.

    2010-01-01

    Third generation biosensor based on Fe-implanted ZnO (Fe-ZnO) thin film has been demonstrated. Implantation of Fe in rf-sputtered ZnO thin film introduces redox center along with shallow donor level and thereby enhance its electron transfer property. Glucose oxidase (GOx), chosen as model enzyme, has been immobilized on the surface of the matrix. Cyclic voltammetry and photometric assay show that the prepared bioelectrode, GOx/Fe-ZnO/ITO/Glass is sensitive to the glucose concentration with enhanced response of 0.326 μA mM -1 cm -2 and low Km of 2.76 mM. The results show promising application of Fe-implanted ZnO thin film as an attractive matrix for third generation biosensing.

  18. Mems-based pzt/pzt bimorph thick film vibration energy harvester

    DEFF Research Database (Denmark)

    Xu, Ruichao; Lei, Anders; Dahl-Petersen, Christian

    2011-01-01

    We describe fabrication and characterization of a significantly improved version of a MEMS-based PZT/PZT thick film bimorph vibration energy harvester with an integrated silicon proof mass. The main advantage of bimorph vibration energy harvesters is that strain energy is not lost in mechanical...... support materials since only PZT is strained, and thus it has a potential for significantly higher output power. An improved process scheme for the energy harvester resulted in a robust fabrication process with a record high fabrication yield of 98.6%. Moreover, the robust fabrication process allowed...... a high pressure treatment of the screen printed PZT thick films prior to sintering, improving the PZT thick film performance and harvester power output reaches 37.1 μW at 1 g....

  19. Electroplated Fe-Co-Ni films prepared in ammonium-chloride-based plating baths

    Science.gov (United States)

    Yanai, T.; Koda, K.; Kaji, J.; Aramaki, H.; Eguchi, K.; Takashima, K.; Nakano, M.; Fukunaga, H.

    2018-05-01

    We electroplated Fe-Co-Ni films in ammonium-chloride-based plating baths, and investigated the effect of the Co content on the magnetic properties and the structural ones of the as-plated films. The coercivity increased abruptly when the Co content become more than 60 at.%. As the rough surfaces were observed in the high Co content region, we considered that degradation of the surface is a factor of the abrupt increase in the coercivity. From the XRD analysis, we found that another factor of the abrupt increase is fcc-bcc phase transformation, and concluded that we need to keep the fcc structure to obtain Fe-Co-Ni films with low coercivity.

  20. Fabrication and characterization of MEMS-based PZT/PZT bimorph thick film vibration energy harvesters

    DEFF Research Database (Denmark)

    Xu, Ruichao; Lei, Anders; Dahl-Petersen, Christian

    2012-01-01

    We describe the fabrication and characterization of a significantly improved version of a microelectromechanical system-based PZT/PZT thick film bimorph vibration energy harvester with an integrated silicon proof mass; the harvester is fabricated in a fully monolithic process. The main advantage...... yield of 98%. The robust fabrication process allowed a high pressure treatment of the screen printed PZT thick films prior to sintering. The high pressure treatment improved the PZT thick film performance and increased the harvester power output to 37.1 μW at 1 g root mean square acceleration. We also...... characterize the harvester performance when only one of the PZT layers is used while the other is left open or short circuit....

  1. Removing flicker based on sparse color correspondences in old film restoration

    Science.gov (United States)

    Huang, Xi; Ding, Youdong; Yu, Bing; Xia, Tianran

    2018-04-01

    In the long history of human civilization, archived film is an indispensable part of it, and using digital method to repair damaged film is also a mainstream trend nowadays. In this paper, we propose a sparse color correspondences based technique to remove fading flicker for old films. Our model, combined with multi frame images to establish a simple correction model, includes three key steps. Firstly, we recover sparse color correspondences in the input frames to build a matrix with many missing entries. Secondly, we present a low-rank matrix factorization approach to estimate the unknown parameters of this model. Finally, we adopt a two-step strategy that divide the estimated parameters into reference frame parameters for color recovery correction and other frame parameters for color consistency correction to remove flicker. Our method combined multi-frames takes continuity of the input sequence into account, and the experimental results show the method can remove fading flicker efficiently.

  2. Third generation biosensing matrix based on Fe-implanted ZnO thin film

    Science.gov (United States)

    Saha, Shibu; Gupta, Vinay; Sreenivas, K.; Tan, H. H.; Jagadish, C.

    2010-09-01

    Third generation biosensor based on Fe-implanted ZnO (Fe-ZnO) thin film has been demonstrated. Implantation of Fe in rf-sputtered ZnO thin film introduces redox center along with shallow donor level and thereby enhance its electron transfer property. Glucose oxidase (GOx), chosen as model enzyme, has been immobilized on the surface of the matrix. Cyclic voltammetry and photometric assay show that the prepared bioelectrode, GOx/Fe-ZnO/ITO/Glass is sensitive to the glucose concentration with enhanced response of 0.326 μA mM-1 cm-2 and low Km of 2.76 mM. The results show promising application of Fe-implanted ZnO thin film as an attractive matrix for third generation biosensing.

  3. Hydrazine-based deposition route for device-quality CIGS films

    International Nuclear Information System (INIS)

    Mitzi, David B.; Yuan, Min; Liu, Wei; Kellock, Andrew J.; Chey, S. Jay; Gignac, Lynne; Schrott, Alex G.

    2009-01-01

    A simple solution-based approach for depositing CIGS (Cu-In-Ga-Se/S) absorber layers is discussed, with an emphasis on film characterization, interfacial properties and integration into photovoltaic devices. The process involves incorporating all metal and chalcogenide components into a single hydrazine-based solution, spin coating a precursor film, and heat treating in an inert atmosphere, to form the desired CIGS film with up to micron-scaled film thickness and grain size. PV devices (glass/Mo/CIGS/CdS/i-ZnO/ITO) employing the spin-coated CIGS and using processing temperatures below 500 deg. C have yielded power conversion efficiencies of up to 10% (AM 1.5 illumination), without the need for a post-CIGS-deposition treatment in a gaseous Se source or a cyanide-based bath etch. Short-duration low-temperature (T < 200 deg. C ) oxygen treatment of completed devices is shown to have a positive impact on the performance of initially underperforming cells, thereby enabling better performance in devices prepared at temperatures below 500 deg. C

  4. Hydrazine-based deposition route for device-quality CIGS films

    Energy Technology Data Exchange (ETDEWEB)

    Mitzi, David B. [IBM T. J. Watson Research Center, P. O. Box 218, Yorktown Heights, NY 10598 (United States)], E-mail: dmitzi@us.ibm.com; Yuan, Min; Liu, Wei [IBM T. J. Watson Research Center, P. O. Box 218, Yorktown Heights, NY 10598 (United States); Kellock, Andrew J [IBM Almaden Research Center, 650 Harry Rd, San Jose, CA 95120 (United States); Chey, S Jay; Gignac, Lynne; Schrott, Alex G [IBM T. J. Watson Research Center, P. O. Box 218, Yorktown Heights, NY 10598 (United States)

    2009-02-02

    A simple solution-based approach for depositing CIGS (Cu-In-Ga-Se/S) absorber layers is discussed, with an emphasis on film characterization, interfacial properties and integration into photovoltaic devices. The process involves incorporating all metal and chalcogenide components into a single hydrazine-based solution, spin coating a precursor film, and heat treating in an inert atmosphere, to form the desired CIGS film with up to micron-scaled film thickness and grain size. PV devices (glass/Mo/CIGS/CdS/i-ZnO/ITO) employing the spin-coated CIGS and using processing temperatures below 500 deg. C have yielded power conversion efficiencies of up to 10% (AM 1.5 illumination), without the need for a post-CIGS-deposition treatment in a gaseous Se source or a cyanide-based bath etch. Short-duration low-temperature (T < 200 deg. C ) oxygen treatment of completed devices is shown to have a positive impact on the performance of initially underperforming cells, thereby enabling better performance in devices prepared at temperatures below 500 deg. C.

  5. SU-F-18C-10: Clinical Implementation of Radiochromic Film Based CTDI Measurements

    International Nuclear Information System (INIS)

    Quintero, C; Seuntjens, J; Devic, S; Tomic, N; DeBlois, F

    2014-01-01

    Purpose: To evaluate accuracy and reproducibility of a radiochromic film-based protocol to measure computer tomography dose index (CTDI) as a part of annual QA on CT scanners and kV CBCT systems attached to linear accelerators. Methods: Energy dependence of Gafchromic XR-QA2(R) film model was tested over imaging beam qualities (50 – 140 kVp). Film pieces were irradiated in air to known values of air kerma in air (up to 10 cGy). Change in film reflectance was determined with an in-house written code using images produced by a flatbed document scanner. Calibration curves for each beam quality were created, and film responses for same air-kerma values were compared.Sets of film strips were placed into holes of a CTDI phantom and irradiated for several clinical scanning protocols on CT-simulators and CBCT systems. Film reflectance change was converted into dose to water and used to calculate CTDIvol values. Measured CTDIvol values were compared to tabulated CTDIvol values. Results: Average variations of ±5.2% in the mean film reflectance change were observed in the energy range of 80 to 140 keV, and 11.1% between 50 and 140 keV. The averaged measured CTDI values presented a mean variation for the same machine and protocol of 2.6%. However, measured CTDI values were in average 10% lower than tabulated CTDI values for CT-simulators, and 44% higher for CBCT systems. Conclusion: We found that in relatively broad range of beam qualities used in diagnostic radiology variation of film response is within ±5% resulting in ±15% systematic error in dose estimates if a single calibration curve is used. Relatively large discrepancy between measured and tabulated CTDI values for different protocols and imaging systems used within radiotherapy department strongly support the trend towards replacing CTDI value with equilibrium dose measurement in the center of cylindrical phantom as suggested by TG-111. This work was supported by the Natural Sciences and Engineering Research

  6. Electrochemical investigation of electrochromic devices based on NiO and WO3 films using different lithium salts electrolytes

    International Nuclear Information System (INIS)

    Wei, Youxiu; Chen, Mu; Liu, Weiming; Li, Lei; Yan, Yue

    2017-01-01

    Highlights: •ECDs based on NiO and WO 3 films using different electrolytes were fabricated. •Effect of different electrolytes on films and ECDs was investigated. •Applied voltage distribution on NiO and WO 3 electrodes in an ECD was studied. •Voltage distribution on films was unbalanced and associated with electrolyte. •Films have different impedance behavior in different states and electrolytes. -- Abstract: Electrochromic devices (ECDs) with different liquid electrolytes were fabricated using NiO film as counter electrode, WO 3 film as working electrode. The effect of liquid electrolytes containing different lithium salts (LiClO 4 , LiPF 6 , LiTFSI) on films and ECDs was investigated, such as transmittance change, charge density, memory effect and cyclic stability. Films or ECDs using LiPF 6 electrolyte have excellent electrochromic properties but low cyclic stability, compared with LiClO 4 and LiTFSI electrolytes. In order to deeply understand the effect of electrolyte on films and devices, the voltage distribution of films based on an analog cell and electrochemical impedance spectroscopy (EIS) were measured and analyzed in different lithium salts electrolytes. Results show that voltage distribution and EIS characteristics of films have obvious difference in liquid LiClO 4 , LiPF 6 and LiTFSI electrolytes. Voltage distribution on NiO and WO 3 films is unbalanced and the impedance of films in bleached and colored states is different in the same electrolyte.

  7. Incorporation of citrus essential oils into bacterial cellulose-based edible films and assessment of their physical properties

    Science.gov (United States)

    Indrarti, L.; Indriyati

    2017-03-01

    The use of edible films in food protection and preservation has recently gained more interest since they offer several advantages over synthetic packaging materials. Biocellulose (BC) offers great opportunity as edible film due to their unique physical and mechanical properties. In this study, biocellulose films were prepared by solution casting with addition of 30% carboxymethyl cellulose (CMC) and 30% glycerol as the homogenizer and plasticizer, respectively. Furthermore, various citrus essential oils (EOs) including lemon, lime, and sweet orange were added at 50% w/w of BC dried weight. The solutions were then cast on the tray and allowed to dry in the air convection oven at 40°C overnight. The films were characterized for water solubility, tensile strength (TS), elongation at break (EB), water vapour transmission rate (WVTR), and color. Those characteristics may influence consumer acceptability of the packaged products. Results revealed that addition of lemon and sweet orange EOs into BC-based edible film decreased water solubility and TS, but improved EB, as these oils acted as plasticizers in the film. However, different trend was observed for BC-based film incorporated with lime oil, which had higher solubility and TS, but lower EB and WVTR compared with that of control film. Addition of citrus EOs into BC-based films did not have much effect on color properties as stated in L*, a*, and b* values.

  8. The preparation of ZnO based gas-sensing thin films by ink-jet printing method

    International Nuclear Information System (INIS)

    Shen Wenfeng; Zhao Yan; Zhang Caibei

    2005-01-01

    An ink-jet printing technique was applied to prepare ZnO based gas-sensing thin films. ZnO inks with appropriate viscosity and surface tension were prepared by sol-gel techniques, and printed onto substrates using a commercial printer. After the drying and heating treatment processes, continuous ZnO films were formed and studied by scanning electron microscopy, X-ray diffraction and by a home-made gas sensitivity measuring system. It was found that the morphology and electrical properties of the films changed significantly with the thickness of the films, which can be adjusted simply by printing on the film with increasing frequency. Highest resistance and sensitivity to acetone vapor were obtained when the film was prepared by printing only once on it. Different dopants with certain concentrations could be added into the films by printing with different dopant inks and printing frequency. All Pd, Ag, and ZrO 2 dopants increased both the resistivity and the sensitivity of the films (180 ppm acetone). This work showed that the ink-jet printing technique was a convenient and low cost method to prepare films with controlled film thickness and dopant concentration

  9. Magnetic Properties of FeNi-Based Thin Film Materials with Different Additives

    Directory of Open Access Journals (Sweden)

    Cai Liang

    2014-07-01

    Full Text Available This paper presents a study of FeNi-based thin film materials deposited with Mo, Al and B using a co-sputtering process. The existence of soft magnetic properties in combination with strong magneto-mechanical coupling makes these materials attractive for sensor applications. Our findings show that FeNi deposited with Mo or Al yields magnetically soft materials and that depositing with B further increases the softness. The out-of-plane magnetic anisotropy of FeNi thin films is reduced by depositing with Al and completely removed by depositing with B. The effect of depositing with Mo is dependent on the Mo concentration. The coercivity of FeNiMo and FeNiAl is reduced to less than a half of that of FeNi, and a value as low as 40 A/m is obtained for FeNiB. The surfaces of the obtained FeNiMo, FeNiAl and FeNiB thin films reveal very different morphologies. The surface of FeNiMo shows nano-cracks, while the FeNiAl films show large clusters and fewer nano-cracks. When FeNi is deposited with B, a very smooth morphology is obtained. The crystal structure of FeNiMo strongly depends on the depositant concentration and changes into an amorphous structure at a higher Mo level. FeNiAl thin films remain polycrystalline, even at a very high concentration of Al, and FeNiB films are amorphous, even at a very low concentration of B.

  10. Magnetic properties of FeNi-based thin film materials with different additives

    KAUST Repository

    Liang, C.

    2014-07-04

    This paper presents a study of FeNi-based thin film materials deposited with Mo, Al and B using a co-sputtering process. The existence of soft magnetic properties in combination with strong magneto-mechanical coupling makes these materials attractive for sensor applications. Our findings show that FeNi deposited with Mo or Al yields magnetically soft materials and that depositing with B further increases the softness. The out-of-plane magnetic anisotropy of FeNi thin films is reduced by depositing with Al and completely removed by depositing with B. The effect of depositing with Mo is dependent on the Mo concentration. The coercivity of FeNiMo and FeNiAl is reduced to less than a half of that of FeNi, and a value as low as 40 A/m is obtained for FeNiB. The surfaces of the obtained FeNiMo, FeNiAl and FeNiB thin films reveal very different morphologies. The surface of FeNiMo shows nano-cracks, while the FeNiAl films show large clusters and fewer nano-cracks. When FeNi is deposited with B, a very smooth morphology is obtained. The crystal structure of FeNiMo strongly depends on the depositant concentration and changes into an amorphous structure at a higher Mo level. FeNiAl thin films remain polycrystalline, even at a very high concentration of Al, and FeNiB films are amorphous, even at a very low concentration of B. 2014 by the authors.

  11. Extremely Efficient Design of Organic Thin Film Solar Cells via Learning-Based Optimization

    Directory of Open Access Journals (Sweden)

    Mine Kaya

    2017-11-01

    Full Text Available Design of efficient thin film photovoltaic (PV cells require optical power absorption to be computed inside a nano-scale structure of photovoltaics, dielectric and plasmonic materials. Calculating power absorption requires Maxwell’s electromagnetic equations which are solved using numerical methods, such as finite difference time domain (FDTD. The computational cost of thin film PV cell design and optimization is therefore cumbersome, due to successive FDTD simulations. This cost can be reduced using a surrogate-based optimization procedure. In this study, we deploy neural networks (NNs to model optical absorption in organic PV structures. We use the corresponding surrogate-based optimization procedure to maximize light trapping inside thin film organic cells infused with metallic particles. Metallic particles are known to induce plasmonic effects at the metal–semiconductor interface, thus increasing absorption. However, a rigorous design procedure is required to achieve the best performance within known design guidelines. As a result of using NNs to model thin film solar absorption, the required time to complete optimization is decreased by more than five times. The obtained NN model is found to be very reliable. The optimization procedure results in absorption enhancement greater than 200%. Furthermore, we demonstrate that once a reliable surrogate model such as the developed NN is available, it can be used for alternative analyses on the proposed design, such as uncertainty analysis (e.g., fabrication error.

  12. Coefficient of Friction Between Carboxymethylated Hyaluronic Acid-Based Polymer Films and the Ocular Surface.

    Science.gov (United States)

    Colter, Jourdan; Wirostko, Barbara; Coats, Brittany

    2017-12-01

    Hyaluronic acid-based polymer films are emerging as drug-delivery vehicles for local and continuous drug administration to the eye. The highly lubricating hyaluronic acid increases comfort, but displaces films from the eye, reducing drug exposure and efficacy. Previous studies have shown that careful control of the surface interaction of the film with the eye is critical for improved retention. In this study, the frictional interaction of a carboxymethylated, hyaluronic acid-based polymer (CMHA-S) with and without methylcellulose was quantified against ovine and human sclera at three axial loads (0.3, 0.5, and 0.7 N) and four sliding velocities (0.3, 1.0, 10, and 30 mm/s). Static coefficients of friction significantly increased with rate (P Friction became more rate-dependent when methylcellulose was added to CMHA-S. Kinetic coefficient of friction was not affected by rate, and averaged 0.15 ± 0.1. Methylcellulose increased CMHA-S static and kinetic friction by 60% and 80%, respectively, but was also prone to wear during testing. These data suggest that methylcellulose can be used to create a friction differential on the film, but a potentially increased degradation rate with the methylcellulose must be considered in the design.

  13. Pentacene-Based Thin Film Transistor with Inkjet-Printed Nanocomposite High-K Dielectrics

    Directory of Open Access Journals (Sweden)

    Chao-Te Liu

    2012-01-01

    Full Text Available The nanocomposite gate insulating film of a pentacene-based thin film transistor was deposited by inkjet printing. In this study, utilizing the pearl miller to crumble the agglomerations and the dispersant to well stabilize the dispersion of nano-TiO2 particles in the polymer matrix of the ink increases the dose concentration for pico-jetting, which could be as the gate dielectric film made by inkjet printing without the photography process. Finally, we realized top contact pentacene-TFTs and successfully accomplished the purpose of directly patternability and increase the performance of the device based on the nanocomposite by inkjet printing. These devices exhibited p-channel TFT characteristics with a high field-effect mobility (a saturation mobility of ̃0.58 cm2 V−1 s−1, a large current ratio (>103 and a low operation voltage (<6 V. Furthermore, we accorded the deposited mechanisms which caused the interface difference between of inkjet printing and spin coating. And we used XRD, SEM, Raman spectroscopy to help us analyze the transfer characteristics of pentacene films and the performance of OTFTs.

  14. Study of Fe-Ni-Si-B alloy and films on its base by X-ray photospectroscopy method

    International Nuclear Information System (INIS)

    Kozlenko, V.G.; Parfenenok, M.A.; Pukhov, I.K.; Shaposhnikov, A.N.; Shirkov, A.V.

    1983-01-01

    By the method of X ray photoelectron spectroscopy the chemical composition of Fe-Ni-Si-B alloy and films on its base prepared by ion-plasma sputtering is investigated. The identity of chemical bonds in film samples and initial target is revealed, realized are in them mostly Fe-B, Ni-C, Si-Si interatomic bonds. It is shown that lono. films contact with atmosphere is the cause of difference of film composition in the near-surface region (up to 100 nm) from its main volume composition

  15. Poly(N-isopropylacrylamide) hydrogel-based shape-adjustable polyimide films triggered by near-human-body temperature.

    Science.gov (United States)

    Huanqing Cui; Xuemin Du; Juan Wang; Tianhong Tang; Tianzhun Wu

    2016-08-01

    Hydrogel-based shape-adjustable films were successfully fabricated via grafting poly(N-isopropylacrylamide) (PNIPAM) onto one side of polyimide (PI) films. The prepared PI-g-PNIPAM films exhibited rapid, reversible, and repeatable bending/unbending property by heating to near-human-body temperature (37 °C) or cooling to 25 °C. The excellent property of PI-g-PNIPAM films resulted from a lower critical solution temperature (LCST) of PNIPAM at about 32 °C. Varying the thickness of PNIPAM hydrogel layer regulated the thermo-responsive shape bending degree and response speed of PI-g-PNIPAM films. The thermo-induced shrinkage of hydrogel layers can tune the curvature of PI films, which have potential applications in the field of wearable and implantable devices.

  16. Enhanced electrochromic properties of TiO2 nanoporous film prepared based on an assistance of polyethylene glycol

    Science.gov (United States)

    Xu, Shunjian; Luo, Xiaorui; Xiao, Zonghu; Luo, Yongping; Zhong, Wei; Ou, Hui; Li, Yinshuai

    2017-01-01

    Polyethylene glycol (PEG) was employed as pore-forming agent to prepare TiO2 nanoporous film based on spin-coating a TiO2 nanoparticle mixed paste on fluorine doped tin oxide (FTO) glass. The electrochromic and optical properties of the obtained TiO2 film were investigated by cyclic voltammetry (CV), chronoamperometry (CA) and UV-Vis spectrophotometer. The results show that the PEG in the mixed paste endows the TiO2 film with well-developed porous structure and improves the uniformity of the TiO2 film, which are helpful for the rapid intercalation and extraction of lithium ions within the TiO2 film and the strengthening of the diffuse reflection of visible light in the TiO2 film. As a result, the TiO2 film derived from the mixed paste with PEG displays higher electrochemical activity and more excellent electrochromic performances compared with the TiO2 film derived from the mixed paste without PEG. The switching times of coloration/bleaching are respectively 10.16/5.65 and 12.77/6.13 s for the TiO2 films with PEG and without PEG. The maximum value of the optical contrast of the TiO2 film with PEG is 21.2% while that of the optical contrast of the TiO2 film without PEG is 14.9%. Furthermore, the TiO2 film with PEG has better stability of the colored state than the TiO2 film without PEG.

  17. Carbon-based layer-by-layer nanostructures: from films to hollow capsules

    Science.gov (United States)

    Hong, Jinkee; Han, Jung Yeon; Yoon, Hyunsik; Joo, Piljae; Lee, Taemin; Seo, Eunyong; Char, Kookheon; Kim, Byeong-Su

    2011-11-01

    Over the past years, the layer-by-layer (LbL) assembly has been widely developed as one of the most powerful techniques to prepare multifunctional films with desired functions, structures and morphologies because of its versatility in the process steps in both material and substrate choices. Among various functional nanoscale objects, carbon-based nanomaterials, such as carbon nanotubes and graphene sheets, are promising candidates for emerging science and technology with their unique physical, chemical, and mechanical properties. In particular, carbon-based functional multilayer coatings based on the LbL assembly are currently being actively pursued as conducting electrodes, batteries, solar cells, supercapacitors, fuel cells and sensor applications. In this article, we give an overview on the use of carbon materials in nanostructured films and capsules prepared by the LbL assembly with the aim of unraveling the unique features and their applications of carbon multilayers prepared by the LbL assembly.

  18. S Sensors: Fumarate-Based fcu-MOF Thin Film Grown on a Capacitive Interdigitated Electrode

    KAUST Repository

    Yassine, Omar

    2016-10-31

    Herein we report the fabrication of an advanced sensor for the detection of hydrogen sulfide (H2S) at room temperature, using thin films of rare-earth metal (RE)-based metal-organic framework (MOF) with underlying fcu topology. This unique MOF-based sensor is made via the insitu growth of fumarate-based fcu-MOF (fum-fcu-MOF) thin film on a capacitive interdigitated electrode. The sensor showed a remarkable detection sensitivity for H2S at concentrations down to 100ppb, with the lower detection limit around 5ppb. The fum-fcu-MOF sensor exhibits a highly desirable detection selectivity towards H2S vs. CH4, NO2, H2, and C7H8 as well as an outstanding H2S sensing stability as compared to other reported MOFs. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Investigation of physicochemical and microbiological characteristics of prepared films containing nanoparticles of titanium oxide based on soy flour polysaccharide

    Directory of Open Access Journals (Sweden)

    D Salarbashi

    2016-11-01

    Full Text Available Introduction: The natural derived biopolymers are highly interested in recent years. These polymers are considering as the alternative for un-biodegradable plastic films. This is due to the low cost and their availability from biodegradable and renewable sources. In this study, the effect of different concentrations of Tio2 nanoparticles on physicochemical and microbiological characteristics of prepared edible films based on soy flour soluble polysaccharide was investigated. MethodS: The nanocomposite films were prepared by adding the Tio2 nanoparticles (5, 10 and 15%/ db to the soy flour. In order to investigate the physicochemical and microbiological properties, the resulted nanocomposite films were synthetized based on the casting method. Results: When the content of nanoparticles increased, the moisture content and solubility of the film specimens were significantly decreased, whereas the mechanical resistance was significantly increased. Tio2 nanoparticle was highly effective against basillus cereus, staphylococus ureus and staphylococuss epidermidis. Meanwhile, MIC and MBC of molds were not affected by these films. MIC for penicilium expansum was significantly affected when the Tio2 nanoparticles increased. Conclusion: the results indicated that Tio2 nanoparticles are applicable into the polysaccharide soy films. The nanocomposite film developed in the current study could be used in food applications and as a biodegradable film.

  20. Benefits of carbon addition on the hydrogen absorption properties of Mg-based thin films grown by Pulsed Laser Deposition

    International Nuclear Information System (INIS)

    Darok, X.; Rougier, A.; Bhat, V.; Aymard, L.; Dupont, L.; Laffont, L.; Tarascon, J.-M.

    2006-01-01

    Mg-Ni thin films were grown using Pulsed Laser Deposition. In situ optical changes from shiny metallic to transparent states were observed for films deposited in vacuum and under an Ar/H 2 gas mixture (93/7%), respectively. Optical changes were also achieved by ex situ hydrogenation under hydrogen gas pressure of 15 bars at 200 deg. C. However, after ex situ hydrogenation, the optical transmittance of the Mg-based hydrogenated thin films did not exceed 25%. Such limitation was attributed to oxygen contamination, as deduced by High Resolution Transmission Electron Microscopy observations, showing the co-existence of both Mg-based and MgO phases for as-deposited films. A significant decrease in oxygen contamination was successfully achieved with the addition of carbon, leading to the preparation of (Mg-based)-C x (x < 20%) thin films showing a faster and easier hydrogenation

  1. Quantifying oxygen in paper-based cell cultures with luminescent thin film sensors.

    Science.gov (United States)

    Boyce, Matthew W; Kenney, Rachael M; Truong, Andrew S; Lockett, Matthew R

    2016-04-01

    Paper-based scaffolds are an attractive material for generating 3D tissue-like cultures because paper is readily available and does not require specialized equipment to pattern, cut, or use. By controlling the exchange of fresh culture medium with the paper-based scaffolds, we can engineer diffusion-dominated environments similar to those found in spheroids or solid tumors. Oxygen tension directly regulates cellular phenotype and invasiveness through hypoxia-inducible transcription factors and also has chemotactic properties. To date, gradients of oxygen generated in the paper-based cultures have relied on cellular response-based readouts. In this work, we prepared a luminescent thin film capable of quantifying oxygen tensions in apposed cell-containing paper-based scaffolds. The oxygen sensors, which are polystyrene films containing a Pd(II) tetrakis(pentafluorophenyl)porphyrin dye, are photostable, stable in culture conditions, and not cytotoxic. They have a linear response for oxygen tensions ranging from 0 to 160 mmHg O2, and a Stern-Volmer constant (K sv) of 0.239 ± 0.003 mmHg O2 (-1). We used these oxygen-sensing films to measure the spatial and temporal changes in oxygen tension for paper-based cultures containing a breast cancer line that was engineered to constitutively express a fluorescent protein. By acquiring images of the oxygen-sensing film and the fluorescently labeled cells, we were able to approximate the oxygen consumption rates of the cells in our cultures.

  2. Reinforced cassava starch based edible film incorporated with essential oil and sodium bentonite nanoclay as food packaging material.

    Science.gov (United States)

    Iamareerat, Butsadee; Singh, Manisha; Sadiq, Muhammad Bilal; Anal, Anil Kumar

    2018-05-01

    Biodegradable packaging in food materials is a green technology based novel approach to replace the synthetic and conventional packaging systems. This study is aimed to formulate the biodegradable cassava starch based films incorporated with cinnamon essential oil and sodium bentonite clay nanoparticles. The films were characterized for their application as a packaging material for meatballs. The cassava starch films incorporated with sodium bentonite and cinnamon oil showed significant antibacterial potential against all test bacteria; Escherichia coli , Salmonella typhimurium and Staphylococcus aureus. Antibacterial effect of films increased significantly when the concentration of cinnamon oil was increased. The cassava starch film incorporated with 0.75% (w/w) sodium bentonite, 2% (w/w) glycerol and 2.5% (w/w) cinnamon oil was selected based on physical, mechanical and antibacterial potential to evaluate shelf life of meatballs. The meatballs stored at ambient temperature in cassava starch film incorporated with cinnamon oil and nanoclay, significantly inhibited the microbial growth till 96 h below the FDA limits (10 6  CFU/g) in foods compared to control films that exceeded above the limit within 48 h. Hence cassava starch based film incorporated with essential oils and clay nanoparticles can be an alternate approach as a packaging material for food industries to prolong the shelf life of products.

  3. Superhydrophobic cellulose-based bionanocomposite films from Pickering emulsions

    Science.gov (United States)

    Bayer, Ilker S.; Steele, Adam; Martorana, Philip J.; Loth, Eric; Miller, Lance

    2009-04-01

    Inherently superhydrophobic and flexible cellulose-based bionanocomposites were fabricated from solid stabilized (Pickering) emulsions. Emulsions were formed by dispersing cyclosiloxanes in water stabilized by layered silicate particles and were subsequently modified by blending into a zinc oxide nanofluid. The polymer matrix was a blend of cellulose nitrate and fluoroacrylic polymer (Zonyl 8740) precompatibilized in solution. Coatings were spray cast onto aluminum substrates from polymer blends dispersed in modified Pickering emulsions. No postsurface treatment was required to induce superhydrophobicity. Effect of antiseptic additives on bionanocomposite superhydrophobicity is also discussed. Replacing cellulose nitrate with commercial liquid bandage solutions produced identical superhydrophobic coatings.

  4. Flexible Ultrahigh-Temperature Polymer-Based Dielectrics with High Permittivity for Film Capacitor Applications

    Directory of Open Access Journals (Sweden)

    Zejun Pu

    2017-11-01

    Full Text Available In this report, flexible cross-linked polyarylene ether nitrile/functionalized barium titanate(CPEN/F-BaTiO3 dielectrics films with high permittivitywere prepared and characterized. The effects of both the F-BaTiO3 and matrix curing on the mechanical, thermal and dielectric properties of the CPEN/F-BaTiO3 dielectric films were investigated in detail. Compared to pristine BaTiO3, the surface modified BaTiO3 particles effectively improved their dispersibility and interfacial adhesion in the polymer matrix. Moreover, the introduction of F-BaTiO3 particles enhanced dielectric properties of the composites, with a relatively high permittivity of 15.2 and a quite low loss tangent of 0.022 (1 kHz when particle contents of 40 wt % were utilized. In addition, the cyano (–CN groups of functional layer also can serve as potential sites for cross-linking with polyarylene ether nitrile terminated phthalonitrile (PEN-Ph matrix and make it transform from thermoplastic to thermosetting. Comparing with the pure PEN-ph film, the latter results indicated that the formation of cross-linked network in the polymer-based system resulted in increased tensile strength by ~67%, improved glass transition temperature (Tg by ~190 °C. More importantly, the CPEN/F-BaTiO3 composite films filled with 30 wt % F-BaTiO3 particles showed greater energy density by nearly 190% when compared to pure CPEN film. These findings enable broader applications of PEN-based composites in high-performance electronics and energy storage devices materials used at high temperature.

  5. Thick-film textile-based amperometric sensors and biosensors.

    Science.gov (United States)

    Yang, Yang-Li; Chuang, Min-Chieh; Lou, Shyh-Liang; Wang, Joseph

    2010-06-01

    The incorporation of amperometric sensors into clothing through direct screen-printing onto the textile substrate is described. Particular attention is given to electrochemical sensors printed directly on the elastic waist of underwear that offers tight direct contact with the skin. The textile-based printed carbon electrodes have a well-defined appearance with relatively smooth conductor edges and no apparent defects or cracks. Convenient voltammetric and chronoamperometric measurements of 0-3 mM ferrocyanide, 0-25 mM hydrogen peroxide, and 0-100 muM NADH have been documented. The favorable electrochemical behavior is maintained under folding or stretching stress, relevant to the deformation of clothing. The electrochemical performance and tolerance to mechanical stress are influenced by the physical characteristics of the textile substrate. The results indicate the potential of textile-based screen-printed amperometric sensors for future healthcare, sport or military applications. Such future applications would benefit from tailoring the ink composition and printing conditions to meet the specific requirements of the textile substrate.

  6. Deposition and properties of cobalt- and ruthenium-based ultra-thin films

    Science.gov (United States)

    Henderson, Lucas Benjamin

    Future copper interconnect systems will require replacement of the materials that currently comprise both the liner layer(s) and the capping layer. Ruthenium has previously been considered as a material that could function as a single material liner, however its poor ability to prevent copper diffusion makes it incompatible with liner requirements. A recently described chemical vapor deposition route to amorphous ruthenium-phosphorus alloy films could correct this problem by eliminating the grain boundaries found in pure ruthenium films. Bias-temperature stressing of capacitor structures using 5 nm ruthenium-phosphorus film as a barrier to copper diffusion and analysis of the times-to-failure at accelerated temperature and field conditions implies that ruthenium-phosphorus performs acceptably as a diffusion barrier for temperatures above 165°C. The future problems associated with the copper capping layer are primarily due to the poor adhesion between copper and the current Si-based capping layers. Cobalt, which adheres well to copper, has been widely proposed to replace the Si-based materials, but its ability to prevent copper diffusion must be improved if it is to be successfully implemented in the interconnect. Using a dual-source chemistry of dicobaltoctacarbonyl and trimethylphosphine at temperatures from 250-350°C, amorphous cobalt-phosphorus can be deposited by chemical vapor deposition. The films contain elemental cobalt and phosphorus, plus some carbon impurity, which is incorporated in the film as both graphitic and carbidic (bonded to cobalt) carbon. When deposited on copper, the adhesion between the two materials remains strong despite the presence of phosphorus and carbon at the interface, but the selectivity for growth on copper compared to silicon dioxide is poor and must be improved prior to consideration for application in interconnect systems. A single molecule precursor containing both cobalt and phosphorus atoms, tetrakis

  7. Microscopic silicon-based lateral high-aspect-ratio structures for thin film conformality analysis

    International Nuclear Information System (INIS)

    Gao, Feng; Arpiainen, Sanna; Puurunen, Riikka L.

    2015-01-01

    Film conformality is one of the major drivers for the interest in atomic layer deposition (ALD) processes. This work presents new silicon-based microscopic lateral high-aspect-ratio (LHAR) test structures for the analysis of the conformality of thin films deposited by ALD and by other chemical vapor deposition means. The microscopic LHAR structures consist of a lateral cavity inside silicon with a roof supported by pillars. The cavity length (e.g., 20–5000 μm) and cavity height (e.g., 200–1000 nm) can be varied, giving aspect ratios of, e.g., 20:1 to 25 000:1. Film conformality can be analyzed with the microscopic LHAR by several means, as demonstrated for the ALD Al 2 O 3 and TiO 2 processes from Me 3 Al/H 2 O and TiCl 4 /H 2 O. The microscopic LHAR test structures introduced in this work expose a new parameter space for thin film conformality investigations expected to prove useful in the development, tuning and modeling of ALD and other chemical vapor deposition processes

  8. Charge transfer processes on electrodes modified by polymer films of metal complexes with Schiff bases

    International Nuclear Information System (INIS)

    Levin, O.V.; Karushev, M.P.; Timonov, A.M.; Alekseeva, E.V.; Zhang, Shuanghua; Malev, V.V.

    2013-01-01

    Electrochemical properties of glassy carbon electrodes modified by two polymer films of different nickel complexes with Schiff base ligands containing methoxy substituents in their aromatic parts were studied in acetonitrile solutions with cyclic voltammetry, quartz crystal microbalance, atomic force microscopy, and impedance spectroscopy. It was observed that introduction of such substituents leads to a noticeable splitting of cycling voltammetric curves into at least two ox/red transitions. In addition, solvent flows accompanying the counter-ions ones during charging/discharge processes within the films appeared significantly greater than those observed in the case of non-substituted ligands. The obtained impedance results as a whole were satisfactorily treated in scope of the so-called model of homogeneous films with two kinds of charge carriers. However, determinations of the Warburg constant as a function of the electrode potential require additional verifications, at least in the ranges of overlapping ox/red transitions. In particular, it was established that in this region the impedance frequency dependence was some superposition of the diffusion (Warburg) and the pseudo-capacitive constituents. This, most likely, resulted from the presence of three kinds of charge carriers in the film interior

  9. Progress in Thin Film Solar Cells Based on Cu2ZnSnS4

    Directory of Open Access Journals (Sweden)

    Hongxia Wang

    2011-01-01

    Full Text Available The research in thin film solar cells has been dominated by light absorber materials based on CdTe and Cu(In,GaSe2 (CIGS in the last several decades. The concerns of environment impact of cadmium and the limited availability of indium in those materials have driven the research towards developing new substitute light absorbers made from earth abundant, environment benign materials. Cu2ZnSnS4 (CZTS semiconductor material has emerged as one of the most promising candidates for this aim and has attracted considerable interest recently. Significant progress in this relatively new research area has been achieved in the last three years. Over 130 papers on CZTS have been published since 2007, and the majority of them are on the preparation of CZTS thin films by different methods. This paper, will review the wide range of techniques that have been used to deposit CZTS semiconductor thin films. The performance of the thin film solar cells using the CZTS material will also be discussed.

  10. Polymer-Silica nanoparticles composite films as protective coatings for stone-based monuments

    Energy Technology Data Exchange (ETDEWEB)

    Manoudis, P [Department of Chemical Engineering, Aristotle University of Thessaloniki, 54124, Thessaloniki (Greece); Papadopoulou, S [Department of Chemical Engineering, Aristotle University of Thessaloniki, 54124, Thessaloniki (Greece); Karapanagiotis, I [' Ormylia' Art Diagnosis Centre, Ormylia, Chalkidiki, 63071 (Greece); Tsakalof, A [Medical Department, University of Thessaly, Larissa, 41222 (Greece); Zuburtikudis, I [Department of Industrial Design Engineering, TEI of Western Macedonia, Kozani, 50100 (Greece); Panayiotou, C [Department of Chemical Engineering, Aristotle University of Thessaloniki, 54124, Thessaloniki (Greece)

    2007-04-15

    The decrease of surface energy of mineral substrates similar to those used in many stone monuments of cultural heritage by the application of protective polymer coatings along with the simultaneous increase of their surface roughness can increase their ability to repel water substantially. In this work, the effect of artificially induced roughness on the water repellency of mineral substrates coated with protective polymer films was investigated. Natural marble samples or home made calcium carbonate blocks were tried as the mineral substrates. The roughness increase was achieved by mineral chemical etching or by creation of nanoscale binary composition film on the substrate surface. PMMA and PFPE were the polymers used, while different-sized silica nanoparticles were employed for the production of the nanocomposite films. Examination of the coated and uncoated surfaces with profilometry and AFM and measurements of water contact angles reveal a pronounced effect of the surface roughness on water repellency. Especially in the case of nanocomposite coatings, the surfaces become super-hydrophobic. This result indicates that the nanoscale binary composition film scheme, which is characterized by its simplicity and low cost, is a suitable candidate for the water protection of stone-based monuments on large scale.

  11. Polymer-Silica nanoparticles composite films as protective coatings for stone-based monuments

    International Nuclear Information System (INIS)

    Manoudis, P; Papadopoulou, S; Karapanagiotis, I; Tsakalof, A; Zuburtikudis, I; Panayiotou, C

    2007-01-01

    The decrease of surface energy of mineral substrates similar to those used in many stone monuments of cultural heritage by the application of protective polymer coatings along with the simultaneous increase of their surface roughness can increase their ability to repel water substantially. In this work, the effect of artificially induced roughness on the water repellency of mineral substrates coated with protective polymer films was investigated. Natural marble samples or home made calcium carbonate blocks were tried as the mineral substrates. The roughness increase was achieved by mineral chemical etching or by creation of nanoscale binary composition film on the substrate surface. PMMA and PFPE were the polymers used, while different-sized silica nanoparticles were employed for the production of the nanocomposite films. Examination of the coated and uncoated surfaces with profilometry and AFM and measurements of water contact angles reveal a pronounced effect of the surface roughness on water repellency. Especially in the case of nanocomposite coatings, the surfaces become super-hydrophobic. This result indicates that the nanoscale binary composition film scheme, which is characterized by its simplicity and low cost, is a suitable candidate for the water protection of stone-based monuments on large scale

  12. In-situ study of hydriding kinetics in Pd-based thin film systems

    Energy Technology Data Exchange (ETDEWEB)

    Delmelle, Renaud; Proost, Joris [Univ. Catholique de Louvain, Louvain-la-Neuve (Belgium). Div. of Materials and Process Engineering

    2010-07-01

    The hydriding kinetics of Pd thin films has been investigated in detail. The key experimental technique used in this work consists of a high resolution curvature measurement setup, which continuously monitors the reflections of multiple laser beams coming off a cantilevered sample. After mounting the sample inside a vacuum chamber, a H-containing gas mixture is introduced to instantaneously generate a given hydrogen partial pressure (p{sub H2}) inside the chamber. The resulting interaction of H with the Pd layer then leads to a volume expansion of the thin film system. This induces in turn changes in the sample curvature as a result of internal stresses developing in the Pd film during a hydriding cycle. Based on such curvature date obtained in-situ at different p{sub H2}, a two-step model for the kinetics of Pd-hydride formation has been proposed and expressions for the hydrogen adsorption and absorption velocities have been derived. The rate-limiting steps have been identified by studying the p{sub H2}-dependence of these velocities. Furthermore, from our in-situ experimental data, relevant kinetic parameters have been calculated. The effect of dry air exposure of the Pd films on the hydriding kinetics has been considered as well. (orig.)

  13. Complex coacervation for the development of composite edible films based on LM pectin and sodium caseinate.

    Science.gov (United States)

    Eghbal, Noushin; Yarmand, Mohammad Saeid; Mousavi, Mohammad; Degraeve, Pascal; Oulahal, Nadia; Gharsallaoui, Adem

    2016-10-20

    Coacervation between sodium caseinate (CAS) and low methoxyl pectin (LMP) at pH 3 was investigated as a function of protein/polysaccharide ratio. The highest amount of complex coacervates was formed at a CAS/LMP ratio of 2 at which the ζ-potential value was zero and the turbidity reached its highest value. Then, the properties of films based on these complex coacervates were studied. Coacervation resulted in decreasing water content and water sorption of films as the protein concentration increased. The mechanical properties of films were highly influenced by the formation of electrostatic complexes. The highest values of Young's modulus (182.97± 6.48MPa) and tensile strength (15.64±1.74MPa) with a slight increase of elongation at break (9.35±0.10%) were obtained for films prepared at a CAS/LMP ratio equal to 0.05. These findings show that interactions between LMP and CAS can be used to develop innovative packaging containing active molecules. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Potential of kaolin-based particle film barriers for Formosan subterranean termite (Isoptera: Rhinotermitidae) control

    Science.gov (United States)

    Wiltz, B.A.; Woodson, W.D.; Puterka, G.J.

    2010-01-01

    Effects of three particle film products on Formosan subterranean termites, Coptotermes formosanus Shiraki, were evaluated in feeding, tunneling, and contact assays. The particle films, hydrophobic M96-018 and hydrophilic Surround and Surround WP are based on the inert clay mineral kaolin. In 2-week long no-choice feeding tests, significant mortality occurred only with M96-018-coated wood. When a choice was provided, M96-018 and Surround were consumed at higher rates than untreated wood. Surround WP did not differ from controls in either test. In the tunneling assay termites were given the option of crossing a kaolin-sand mixture to reach an alternate food source. After 3-weeks, rates of 1% and 5% M96-018 provided an effective barrier to Formosan termite tunneling, while termites were not stopped by rates as high as 20% Surround and Surround WP. Dust treatments of all three formulations caused significant increases in mortality within 24 h, with mortality rates ranging from 72.0 - 97.3% within 72 h of treatment. The particle films were most effective when moisture levels were low, suggesting that desiccation was the mechanism for mortality. All particle films showed potential for use in above ground applications while hydrophobic M06-018 has the most potential as a soil barrier to subterranean termites.

  15. Characteristics of thin-film transistors based on silicon nitride passivation by excimer laser direct patterning

    International Nuclear Information System (INIS)

    Chen, Chao-Nan; Huang, Jung-Jie

    2013-01-01

    This study explored the removal of silicon nitride using KrF laser ablation technology with a high threshold fluence of 990 mJ/cm 2 . This technology was used for contact hole patterning to fabricate SiN x -passivation-based amorphous-silicon thin films in a transistor device. Compared to the photolithography process, laser direct patterning using KrF laser ablation technology can reduce the number of process steps by at least three. Experimental results showed that the mobility and threshold voltages of thin film transistors patterned using the laser process were 0.16 cm 2 /V-sec and 0.2 V, respectively. The device performance and the test results of gate voltage stress reliability demonstrated that laser direct patterning is a promising alternative to photolithography in the panel manufacturing of thin-film transistors for liquid crystal displays. - Highlights: ► KrF laser ablation technology is used to remove silicon nitride. ► A simple method for direct patterning contact-hole in thin-film-transistor device. ► Laser technology reduced processing by at least three steps

  16. Morphological analysis of co-evaporated blend films based on initial growth for organic photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Shibata, Yosei, E-mail: yosei.shibata@aist.go.jp [Research Center for Photovoltaic Technologies, National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565 (Japan); Taima, Tetsuya [Research Center for Photovoltaic Technologies, National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565 (Japan); Japan Science and Technology Agency, PRESTO, 4-1-8 Honcho, Kawaguchi, Saitama 332-0012 (Japan); Zhou, Ying; Ohashi, Noboru; Kono, Takahiro [Research Center for Photovoltaic Technologies, National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565 (Japan); Yoshida, Yuji, E-mail: yuji.yoshida@aist.go.jp [Research Center for Photovoltaic Technologies, National Institute of Advanced Industrial Science and Technology, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8565 (Japan)

    2015-11-15

    Graphical abstract: - Highlights: • Initial growth mode of co-evaporated films was observed. • Balanced crystal growth leads to improvement of photovoltaic performance. • Crystal growth of fullerene during co-evaporation process was restricted. • The power conversion efficiency of 3% was obtained without electron blocking layer. - Abstract: Bulk heterojunction structures composed of electron donor and acceptor molecules for application in high-performance organic photovoltaics studied. To fabricate these structures, the co-evaporation method in vacuum is commonly applied; however, the details of the crystal growth process during co-evaporation have not yet been established. Here, we focused on structural analysis of blend films composed of phthalocyanine and fullerene based on initial growth stage. Similar crystal growth behavior to that typically observed in single-component molecules is obtained for the films. These results suggest that the competitive crystal growth between donors and acceptors occurs during co-evaporation process. The balance of thin film growth among donor and acceptor molecules can be related to improved photovoltaic performance. The homogeneous blend structure leads to improvement of the power conversion efficiency from 1.2% to 3.0%.

  17. AlScN thin film based surface acoustic wave devices with enhanced microfluidic performance

    International Nuclear Information System (INIS)

    Wang, W B; Xuan, W P; Chen, J K; Wang, X Z; Luo, J K; Fu, Y Q; Chen, J J; Duan, P F; Mayrhofer, P; Bittner, A; Schmid, U

    2016-01-01

    This paper reports the characterization of scandium aluminum nitride (Al 1−xS c xN , x   =  27%) films and discusses surface acoustic wave (SAW) devices based on them. Both AlScN and AlN films were deposited on silicon by sputtering and possessed columnar microstructures with (0 0 0 2) crystal orientation. The AlScN/Si SAW devices showed improved electromechanical coupling coefficients ( K 2 , ∼2%) compared with pure AlN films (<0.5%). The performance of the two types of devices was also investigated and compared, using acoustofluidics as an example. The AlScN/Si SAW devices achieved much lower threshold powers for the acoustic streaming and pumping of liquid droplets, and the acoustic streaming and pumping velocities were 2  ×  and 3  ×  those of the AlN/Si SAW devices, respectively. Mechanical characterization showed that the Young’s modulus and hardness of the AlN film decreased significantly when Sc was doped, and this was responsible for the decreased acoustic velocity and resonant frequency, and the increased temperature coefficient of frequency, of the AlScN SAW devices. (paper)

  18. Glucose Sensing Using Capacitive Biosensor Based on Polyvinylidene Fluoride Thin Film

    Directory of Open Access Journals (Sweden)

    Ambran Hartono

    2018-01-01

    Full Text Available A polyvinylidene fluoride (PVDF film-based capacitive biosensor was developed for glucose sensing. This device consists of a PVDF film sandwiched between two electrodes. A capacitive biosensor measures the dielectric properties of the dielectric layers at the interface between the electrolyte and the electrode. A glucose oxidase (GOx enzyme was immobilized onto the electrode to oxidize glucose. In practice, the biochemical reaction of glucose with the GOx enzyme generates free electron carriers. Consequently, the potential difference between the electrodes is increased, resulting in a measurable voltage output of the biosensor. The device was tested for various glucose concentrations in the range of 0.013 to 5.85 M, and various GOx enzyme concentrations between 4882.8 and 2.5 million units/L. We found that the sensor output increased with increasing glucose concentration up to 5.85 M. These results indicate that the PVDF film-based capacitive biosensors can be properly applied to glucose sensing and provide opportunities for the low-cost fabrication of glucose-based biosensors based on PVDF materials.

  19. CuInSe2-Based Thin-Film Photovoltaic Technology in the Gigawatt Production Era

    Science.gov (United States)

    Kushiya, Katsumi

    2012-10-01

    The objective of this paper is to review current status and future prospect on CuInSe2 (CIS)-based thin-film photovoltaic (PV) technology. In CIS-based thin-film PV technology, total-area cell efficiency in a small-area (i.e., smaller than 1 cm2) solar cell with top grids has been over 20%, while aperture-area efficiency in a large-area (i.e., larger than 800 cm2 as definition) monolithic module is approaching to an 18% milestone. However, most of the companies with CIS-based thin-film PV technology still stay at a production research stage, except Solar Frontier K.K. In July, 2011, Solar Frontier has joined the gigawatt (GW) group by starting up their third facility with a 0.9-GW/year production capacity. They are keeping the closest position to pass a 16% module-efficiency border by transferring the developed technologies in the R&D and accelerating the preparation for the future based on the concept of a product life-cycle management.

  20. Metal nanoparticle film-based room temperature Coulomb transistor.

    Science.gov (United States)

    Willing, Svenja; Lehmann, Hauke; Volkmann, Mirjam; Klinke, Christian

    2017-07-01

    Single-electron transistors would represent an approach to developing less power-consuming microelectronic devices if room temperature operation and industry-compatible fabrication were possible. We present a concept based on stripes of small, self-assembled, colloidal, metal nanoparticles on a back-gate device architecture, which leads to well-defined and well-controllable transistor characteristics. This Coulomb transistor has three main advantages. By using the scalable Langmuir-Blodgett method, we combine high-quality chemically synthesized metal nanoparticles with standard lithography techniques. The resulting transistors show on/off ratios above 90%, reliable and sinusoidal Coulomb oscillations, and room temperature operation. Furthermore, this concept allows for versatile tuning of the device properties such as Coulomb energy gap and threshold voltage, as well as period, position, and strength of the oscillations.

  1. Graphene Ink Film Based Electrochemical Detector for Paracetamol Analysis

    Directory of Open Access Journals (Sweden)

    Li Fu

    2018-01-01

    Full Text Available Graphene ink is a commercialized product in the graphene industry with promising potential application in electronic device design. However, the limitation of the graphene ink is its low electronic performance due to the ink preparation protocol. In this work, we proposed a simple post-treatment of graphene ink coating via electrochemical oxidation. The electronic conductivity of the graphene ink coating was enhanced as expected after the treatment. The proposed electrochemical oxidation treatment also exposes the defects of graphene and triggered an electrocatalytic reaction during the sensing of paracetamol (PA. The overpotential of redox is much lower than conventional PA redox potential, which is favorable for avoiding the interference species. Under optimum conditions, the graphene ink-based electrochemical sensor could linearly detect PA from 10 to 500 micro molar (μM, with a limit of detection of 2.7 μM.

  2. Planar Zeolite Film-Based Potentiometric Gas Sensors Manufactured by a Combined Thick-Film and Electroplating Technique

    Science.gov (United States)

    Marr, Isabella; Reiß, Sebastian; Hagen, Gunter; Moos, Ralf

    2011-01-01

    Zeolites are promising materials in the field of gas sensors. In this technology-oriented paper, a planar setup for potentiometric hydrocarbon and hydrogen gas sensors using zeolites as ionic sodium conductors is presented, in which the Pt-loaded Na-ZSM-5 zeolite is applied using a thick-film technique between two interdigitated gold electrodes and one of them is selectively covered for the first time by an electroplated chromium oxide film. The influence of the sensor temperature, the type of hydrocarbons, the zeolite film thickness, and the chromium oxide film thickness is investigated. The influence of the zeolite on the sensor response is briefly discussed in the light of studies dealing with zeolites as selectivity-enhancing cover layers. PMID:22164042

  3. Controllable film densification and interface flatness for high-performance amorphous indium oxide based thin film transistors

    Energy Technology Data Exchange (ETDEWEB)

    Ou-Yang, Wei, E-mail: OUYANG.Wei@nims.go.jp, E-mail: TSUKAGOSHI.Kazuhito@nims.go.jp; Mitoma, Nobuhiko; Kizu, Takio; Gao, Xu; Lin, Meng-Fang; Tsukagoshi, Kazuhito, E-mail: OUYANG.Wei@nims.go.jp, E-mail: TSUKAGOSHI.Kazuhito@nims.go.jp [International Center for Materials Nanoarchitectronics (WPI-MANA), National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Nabatame, Toshihide [MANA Foundry and MANA Advanced Device Materials Group, National Institute for Materials Science (NIMS), 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan)

    2014-10-20

    To avoid the problem of air sensitive and wet-etched Zn and/or Ga contained amorphous oxide transistors, we propose an alternative amorphous semiconductor of indium silicon tungsten oxide as the channel material for thin film transistors. In this study, we employ the material to reveal the relation between the active thin film and the transistor performance with aid of x-ray reflectivity study. By adjusting the pre-annealing temperature, we find that the film densification and interface flatness between the film and gate insulator are crucial for achieving controllable high-performance transistors. The material and findings in the study are believed helpful for realizing controllable high-performance stable transistors.

  4. Planar Zeolite Film-Based Potentiometric Gas Sensors Manufactured by a Combined Thick-Film and Electroplating Technique

    Directory of Open Access Journals (Sweden)

    Gunter Hagen

    2011-08-01

    Full Text Available Zeolites are promising materials in the field of gas sensors. In this technology-oriented paper, a planar setup for potentiometric hydrocarbon and hydrogen gas sensors using zeolites as ionic sodium conductors is presented, in which the Pt-loaded Na-ZSM-5 zeolite is applied using a thick-film technique between two interdigitated gold electrodes and one of them is selectively covered for the first time by an electroplated chromium oxide film. The influence of the sensor temperature, the type of hydrocarbons, the zeolite film thickness, and the chromium oxide film thickness is investigated. The influence of the zeolite on the sensor response is briefly discussed in the light of studies dealing with zeolites as selectivity-enhancing cover layers.

  5. Optical thermal sensor based on cholesteric film refilled with mixture of toluene and ethanol.

    Science.gov (United States)

    Li, Yong; Liu, Yanjun; Luo, Dan

    2017-10-16

    We demonstrate an optical thermal sensor based on cholesteric film refilled with mixture of toluene and ethanol. The thermal response mechanism is mainly based on the thermal expansion effect induce by toluene, where the ethanol is used for refractive index adjustment to determine the initial refection band position of cholesteric film. The ethanol-toluene mixture was used to adjust the color tunability with the temperature in relation with the habits of people (blue as cold, green as safe and red as hot). A broad temperature range of 86 °C and highly sensitivity of 1.79 nm/ °C are achieved in proposed thermal sensor, where the reflective color red-shifts from blue to red when environmental temperature increases from -6 °C to 80 °C. This battery-free thermal sensor possesses features including simple fabrication, low-cost, and broad temperature sensing range, showing potential application in scientific research and industry.

  6. Patch-based frame interpolation for old films via the guidance of motion paths

    Science.gov (United States)

    Xia, Tianran; Ding, Youdong; Yu, Bing; Huang, Xi

    2018-04-01

    Due to improper preservation, traditional films will appear frame loss after digital. To deal with this problem, this paper presents a new adaptive patch-based method of frame interpolation via the guidance of motion paths. Our method is divided into three steps. Firstly, we compute motion paths between two reference frames using optical flow estimation. Then, the adaptive bidirectional interpolation with holes filled is applied to generate pre-intermediate frames. Finally, using patch match to interpolate intermediate frames with the most similar patches. Since the patch match is based on the pre-intermediate frames that contain the motion paths constraint, we show a natural and inartificial frame interpolation. We test different types of old film sequences and compare with other methods, the results prove that our method has a desired performance without hole or ghost effects.

  7. Alcohol vapours sensor based on thin polyaniline salt film and quartz crystal microbalance.

    Science.gov (United States)

    Ayad, Mohamad M; Torad, Nagy L

    2009-06-15

    A sensor based on the quartz crystal microbalance (QCM) technique was developed for detection of a number of primary aliphatic alcohols such as ethanol, methanol, 1-propanol, and 2-propanol vapours. Detection was based on a sensitive and a thin film of polyaniline, emeraldine salt (ES), coated the QCM electrode. The frequency shifts (Delta f) of the QCM were increased due to the vapour absorption into the ES film. The values of Delta f were found to be linearly correlated with the concentrations of alcohols vapour in mg L(-1). The changes in frequency are due to the hydrophilic character of the ES and the electrostatic interaction as well as the type of the alcohol. The sensor shows a good reproducibility and reversibility. The diffusion and diffusion coefficient (D) of different alcohols vapour were determined. It was found that the sensor follows Fickian kinetics.

  8. Andreev reflexion studies on planar hybrid SNS-junctions based on 122-thin films

    Energy Technology Data Exchange (ETDEWEB)

    Doering, Sebastian; Schmidt, Stefan; Schmidl, Frank; Tympel, Volker; Seidel, Paul [Friedrich-Schiller-Universitaet Jena, Institut fuer Festkoerperphysik, Helmholtzweg 5, Jena (Germany); Haindl, Silvia; Kurth, Fritz; Iida, Kazumasa; Holzapfel, Bernhard [IFW Dresden, Institut fuer Metallische Werkstoffe, 01069 Dresden (Germany)

    2012-07-01

    To investigate the properties of iron-based superconductors, we prepared hybrid junctions in thin film technique. Therefore two geometries were prepared, a planar SNS-junction and an edge junction. The base electrode was made of Ba(Fe{sub 0.9}Co{sub 0.1}){sub 2}As{sub 2} thin films, a sputtered gold layer acts as normal barrier for the planar junction and for the counter electrode we used the conventional superconductor lead. We measured the electrical properties of each electrode, as well as the junctions itself. To obtain information about the order parameter symmetry, we show the differential conductance and compare with different variations of an extended BTK-model. We show differences and commonalities between the results of both junction geometries.

  9. Investigation on synthesis of Bi-based thin films on flat sputter-deposited Ag film by melting process

    International Nuclear Information System (INIS)

    Su Yanjing; Satoh, Yoshimasa; Arisawa, Shunichi; Awane, Toru; Fukuyo, Akihiro; Takano, Yoshihiko; Ishii, Akira; Hatano, Takeshi; Togano, Kazumasa

    2003-01-01

    We report on the fabrication of ribbon-like thin films on flat sputter-deposited Ag films whose surface smoothness remained within the order of tens of nm. It was found that the addition of Pb to the starting material improves the wettability of molten phase and facilitates the growth of Bi-2212 ribbon-like thin films on a flat Ag substrate, and that the increase of Ca and Cu in starting material suppresses the intergrowth of the Bi-2201 phase in ribbon-like thin films. By using (Bi,Pb)-2246 powders, with nominal composition of Bi 1.6 Pb 0.4 Sr 1.6 Ca 3.2 Cu 4.8 O y , as the starting material, the superconducting Bi-2212 ribbon-like thin films with an onset T c at 74 K on a very flat Ag substrate were successfully synthesized. Additionally, the growth mechanism of ribbon-like thin films on flat Ag substrate was investigated by in situ high temperature microscope observation

  10. Influence of different factors on the destruction of films based on polylactic acid and oxidized polyethylene

    Science.gov (United States)

    Podzorova, M. V.; Tertyshnaya, Yu. V.; Pantyukhov, P. V.; Shibryaeva, L. S.; Popov, A. A.; Nikolaeva, S.

    2016-11-01

    Influence of different environmental factors on the degradation of film samples based on polylactic acid and low density polyethylene with the addition of oxidized polyethylene was studied in this work. Different methods were used to find the relationship between degradation and ultraviolet, moisture, oxygen. It was found that the addition of oxidized polyethylene, used as a model of recycled polyethylene, promotes the degradation of blends.

  11. Advanced high temperature superconductor film-based process using RABiTS

    International Nuclear Information System (INIS)

    Goyal, A.; Hawsey, R.A.; Hack, J.; Moon, D.

    2000-01-01

    The purpose of this Cooperative Research and Development Agreement (CRADA) between Lockheed Martin Energy Research Corporation (Contractor), Managing contractor for Oak Ridge National Laboratory (ORNL) and Midwest Superconductivity, Inc. (MSI) and Westinghouse Science and Electric Company (WEC) was to develop the basis for a commercial process for the manufacturing of superconducting tape based on the RABiTS technology developed at ORNL. The chosen method for deposition of YBCO films on RABiTS was Metal Organic chemical Vapor Deposition (MOCVD)

  12. Electrodeposition of CdTe thin film from acetate-based ionic liquid bath

    Science.gov (United States)

    Waldiya, Manmohansingh; Bhagat, Dharini; Mukhopadhyay, Indrajit

    2018-05-01

    CdTe being a direct band gap semiconductor, is mostly used in photovoltaics. Here we present, the synthesis of CdTe thin film on fluorine doped tin oxide (FTO) substrate potentiostatically using 1-butyl-3-methylimidazolium acetate ([Bmim][Ac]) ionic liquid (IL) bath at 90 °C. Major advantages of using electrodeposition involves process simplicity, large scalability & economic viability. Some of the benefits offered by IL electrolytic bath are low vapour pressure, wide electrochemical window, and good ionic mobility. Cd(CH3COO)2 (anhydrous) and TeO2 were used as the source precursors. The IL electrolytic bath temperature was kept at 90 °C for deposition, owing to the limited solubility of TeO2 in [Bmim][Ac] IL at room temperature. Cathodic electrodeposition was carried out using a three electrode cell setup at a constant potential of -1.20 V vs. platinum (Pt) wire. The CdTe/FTO thin film were annealed in argon (Ar) atmosphere. Optical study of nanostructured CdTe film were done using UV-Vis-IR and Raman spectroscopy. Raman analysis confirms the formation of CdTe having surface optics (SO) mode at 160.6 cm-1 and transverse optics (TO) mode at 140.5 cm-1. Elemental Te peaks at 123, 140.5 and 268 cm-1 were also observed. The optical band gap of Ar annealed CdTe thin film were found to be 1.47 eV (absorbance band edge ˜ 846 nm). The optimization of deposition parameters using acetate-based IL electrolytic bath to get nearly stoichiometric CdTe thin film is currently being explored.

  13. Interfacial characteristics of polyethylene terephthalate-based piezoelectric multi-layer films

    International Nuclear Information System (INIS)

    Liu, Z.H.; Pan, C.T.; Chen, Y.C.; Liang, P.H.

    2013-01-01

    The study examines the deformation between interfaces and the adhesion mechanism of multi-layer flexible electronic composites. Indium tin oxide (ITO), aluminum (Al), and zinc oxide (ZnO) were deposited on a polyethylene terephthalate (PET) substrate using radio frequency magnetron sputtering at room temperature to form flexible structures (e.g., ITO/PET, Al/PET, ZnO/ITO/PET, and ZnO/Al/PET) for piezoelectric transducers. ITO and Al films are used as the conductive layers. A ZnO thin film shows a high (002) c-axis preferred orientation at 2θ = 34.45° and excellent piezoelectric properties. Nanoscratching and nano-indention testing were conducted to analyze the adhesion following periodic mechanical stress. Additionally, two Berkovich and conical probes with a curvature radius of 40 nm and 10 μm are examined for the scratching test. A 4-point probe is used to measure the conductive properties. The plastic deformation between the ductile Al film and PET substrate is observed using scanning electron microscopy to examine the chip formation on the ITO/PET. Delamination between the ZnO and Al/PET substrate was not observed. The result suggests that ZnO film has excellent adhesion with Al/PET compared to ITO/PET. - Highlights: ► Interfaces and adhesion mechanism of multi-layer flexible electronic composites ► Polyethylene terephthalate (PET) based flexible structures ► Nano-scratching and nano-indention tests were used to analyze adhesion. ► Using two various probes of Berkovich and conical ► Piezoelectric zinc oxide film has excellent adhesion with aluminum/PET

  14. Benzothienobenzothiophene-based conjugated oligomers as semiconductors for stable organic thin-film transistors.

    Science.gov (United States)

    Yu, Han; Li, Weili; Tian, Hongkun; Wang, Haibo; Yan, Donghang; Zhang, Jingping; Geng, Yanhou; Wang, Fosong

    2014-04-09

    Two benzothienobenzothiophene (BTBT)-based conjugated oligomers, i.e., 2,2'-bi[1]benzothieno[3,2-b][1]benzothiophene (1) and 5,5'-bis([1]benzothieno[3,2-b][1]benzothiophen-2-yl)-2,2'-bithiophene (2), were prepared and characterized. Both oligomers exhibit excellent thermal stability, with 5% weight-loss temperatures (T(L)) above 370 °C; no phase transition was observed before decomposition. The highest occupied molecular orbital (HOMO) levels of 1 and 2 are -5.3 and -4.9 eV, respectively, as measured by ultraviolet photoelectron spectroscopy. Thin-film X-ray diffraction and atomic force microscopy characterizations indicate that both oligomers form highly crystalline films with large domain sizes on octadecyltrimethoxysilane-modified substrates. Organic thin-film transistors with top-contact and bottom-gate geometry based on 1 and 2 exhibited mobilities up to 2.12 cm(2)/V·s for 1 and 1.39 cm(2)/V·s for 2 in an ambient atmosphere. 1-based devices exhibited great air and thermal stabilities, as evidenced by the slight performance degradation after 2 months of storage under ambient conditions and after thermal annealing at temperatures below 250 °C.

  15. Highly Conductive, Transparent Flexible Films Based on Metal Nanoparticle-Carbon Nanotube Composites

    Directory of Open Access Journals (Sweden)

    Wen-Yin Ko

    2013-01-01

    Full Text Available Metallic nanoparticles decorated on MWCNTs based transparent conducting thin films (TCFs show a cheap and efficient option for the applications in touch screens and the replacement of the ITO film because of their interesting properties of electrical conductivity, mechanical property, chemical inertness, and other unique properties, which may not be accessible by their individual components. However, a great challenge that always remains is to develop effective ways to prepare junctions between metallic nanoparticles and MWCNTs for the improvement of high-energy barriers, high contact resistances, and weak interactions which could lead to the formation of poor conducting pathways and result in the CNT-based devices with low mechanical flexibility. Herein, we not only discuss recent progress in the preparation of MNP-CNT flexible TCFs but also describe our research studies in the relevant areas. Our result demonstrated that the MNP-CNT flexible TCFs we prepared could achieve a highly electrical conductivity with the sheet resistance of ~100 ohm/sq with ~80% transmittance at 550 nm even after being bent 500 times. This electrical conductivity is much superior to the performances of other MWCNT-based transparent flexible films, making it favorable for next-generation flexible touch screens and optoelectronic devices.

  16. Overcoming the Instability of Nanoparticle-Based Catalyst Films in Alkaline Electrolyzers by using Self-Assembling and Self-Healing Films

    NARCIS (Netherlands)

    Barwe, Stefan; Masa, Justus; Andronescu, Corina; Mei, Bastian; Schuhmann, Wolfgang; Ventosa, Edgar

    2017-01-01

    Engineering stable electrodes using highly active catalyst nanopowders for electrochemical water splitting remains a challenge. We report an innovative and general approach for attaining highly stable catalyst films with self-healing capability based on the in situ self-assembly of catalyst

  17. Enhanced thermoelectric properties of metal film on bismuth telluride-based materials

    International Nuclear Information System (INIS)

    Chao, Wen Hsuan; Chen, Yi Ray; Tseng, Shih Chun; Yang, Ping Hsing; Wu, Ren Jye; Hwang, Jenn Yeu

    2014-01-01

    Diffusion barriers have a significant influence on the reliability and life time of thermoelectric modules. Although nickel is commonly used as a diffusion barrier in commercial thermoelectric modules, several studies have verified that Ni migrates to bismuth telluride-based material during high temperature cycles and causes a loss in efficacy. In this paper, the influence of metal layers coated to p-type and n-type Bi 2 Te 3 on the interface characterization and thermoelectric property is studied using a RF magnetron sputtering. The findings from this study demonstrate the structural and thermoelectric properties of p-type and n-type Bi 2 Te 3 coated with different metal layers. The crystalline phase and compositional change of the interface between the Bi 2 Te 3 materials and the metal layers were determined using an X-ray diffractometer and scanning electron microscopy with energy dispersive spectroscopy. Formation of NiTe was observed in the sample of Ni/p-type Bi 2 Te 3 based films post-annealed in an N 2 atmosphere at 200 °C. In contrast, no Co x Te y was formed in the sample of Co/p-type Bi 2 Te 3 based films post-annealed at 200 °C. For as-deposited Ni/p-type and n-type Bi 2 Te 3 based legs, the Ni slightly diffused into the Bi 2 Te 3 based legs. A similar phenomenon also occurred in the as-deposited Co/p-type and n-type Bi 2 Te 3 based legs. The Seebeck coefficients of the Co contacts on the Bi 2 Te 3 based material displayed better behavior than those of the Ni contacts on the Bi 2 Te 3 based legs. Thus Co could be a suitable diffusion barrier for bulk Bi 2 Te 3 based material. The observed effects on the thermoelectric and structural properties of metal/Bi 2 Te 3 based material are crucial for understanding the interface between the diffusion barrier and thermoelectric materials. - Highlights: • Interface characterization of metal coated to p-type and n-type Bi 2 Te 3 is studied. • We examined the phase transformation of metal/Bi 2 Te 3 based films

  18. Geometric pre-patterning based tuning of the period doubling onset strain during thin film wrinkling

    Energy Technology Data Exchange (ETDEWEB)

    Saha, Sourabh K. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-02-16

    Wrinkling of supported thin films is an easy-to-implement and low-cost fabrication technique for generation of stretch-tunable periodic micro and nano-scale structures. However, the tunability of such structures is often limited by the emergence of an undesirable period doubled mode at high strains. Predictively tuning the onset strain for period doubling via existing techniques requires one to have extensive knowledge about the nonlinear pattern formation behavior. Herein, a geometric pre-patterning based technique is introduced to delay the onset of period doubling that can be implemented to predictively tune the onset strain even with limited system knowledge. The technique comprises pre-patterning the film/base bilayer with a sinusoidal pattern that has the same period as the natural wrinkle period of the system. The effectiveness of this technique has been verified via physical and computational experiments on the polydimethylsiloxane/glass bilayer system. It is observed that the period doubling onset strain can be increased from the typical value of 20% for flat films to greater than 30% with a modest pre-pattern aspect ratio (2∙amplitude/period) of 0.15. In addition, finite element simulations reveal that (i) the onset strain can be increased up to a limit by increasing the amplitude of the pre-patterns and (ii) the delaying effect can be captured entirely by the pre-pattern geometry. As a result, one can implement this technique even with limited system knowledge, such as material properties or film thickness, by simply replicating pre-existing wrinkled patterns to generate prepatterned bilayers. Thus, geometric pre-patterning is a practical scheme to suppress period doubling that can increase the operating range of stretch-tunable wrinkle-based devices by at least 50%.

  19. THIN FILM-BASED SENSOR FOR MOTOR VEHICLE EXHAUST GAS, NH3, AND CO DETECTION

    Directory of Open Access Journals (Sweden)

    S. Sujarwata

    2016-10-01

    Full Text Available A copper phthalocyanine (CuPc thin film based gas sensor with FET structure and channel length 100 μm has been prepared by VE method and lithography technique to detect NH3, motor cycle exhaust gases and CO. CuPc material layer was deposited on SiO2 by the vacuum evaporator (VE method at room temperature and pressure of 8 x10-4 Pa. The stages of manufacturing gas sensor were Si/SiO2 substrate blenching with ethanol in an ultrasonic cleaner, source, and drain electrodes deposition on the substrate by using a vacuum evaporator, thin film deposition between the source/drain and gate deposition. The sensor response times to NH3, motorcycle exhaust gases and CO were 75 s, 135 s, and 150, respectively. The recovery times were 90 s, 150 s and 225, respectively. It is concluded that the CuPc thin film-based gas sensor with FET structure is the best sensor to detect the NH3 gas.Sensor gas berbasis film tipis copper phthalocyanine (CuPc berstruktur FET dengan panjang channel 100 μm telah dibuatdengan metode VE dan teknik lithography untuk mendeteksi NH3 gas buang kendaraan bermotor dan CO. Lapisan bahan CuPc dideposisikan pada permukaan silikon dioksida (SiO2 dengan metode vacuum evaporator (VE pada temperatur ruang dengan tekanan 8 x10-4 Pa. Tahapan pembuatan sensor gas adalah pencucian substrat Si/SiO2 dengan etanol dalam ultrasonic cleaner, deposisi elektroda source dan drain di atas substrat dengan metode vacuum evaporator, deposisi film tipis diantara source/drain dan deposisi gate. Waktu tanggap sensor terhadap NH3, gas buang kendaraan bermotor dan CO berturut-turut adalah 75 s, 135 s,dan 150 s. Waktu pemulihan berturut-turut adalah 90 s, 150 s,dan 225 s. Disimpulkan bahwa sensor gas berstruktur FET berbasis film tipis CuPc merupakan sensor paling baik untuk mendeteksi adanya gas NH3.

  20. In-situ XPS analysis of oxidized and reduced plasma deposited ruthenium-based thin catalytic films

    Science.gov (United States)

    Balcerzak, Jacek; Redzynia, Wiktor; Tyczkowski, Jacek

    2017-12-01

    A novel in-situ study of the surface molecular structure of catalytically active ruthenium-based films subjected to the oxidation (in oxygen) and reduction (in hydrogen) was performed in a Cat-Cell reactor combined with a XPS spectrometer. The films were produced by the plasma deposition method (PEMOCVD). It was found that the films contained ruthenium at different oxidation states: metallic (Ru0), RuO2 (Ru+4), and other RuOx (Ru+x), of which content could be changed by the oxidation or reduction, depending on the process temperature. These results allow to predict the behavior of the Ru-based catalysts in different redox environments.

  1. Graphene oxide/carbon nanoparticle thin film based IR detector: Surface properties and device characterization

    Directory of Open Access Journals (Sweden)

    Farzana Aktar Chowdhury

    2015-10-01

    Full Text Available This work deals with the synthesis, characterization, and application of carbon nanoparticles (CNP adorned graphene oxide (GO nanocomposite materials. Here we mainly focus on an emerging topic in modern research field presenting GO-CNP nanocomposite as a infrared (IR radiation detector device. GO-CNP thin film devices were fabricated from liquid phase at ambient condition where no modifying treatments were necessary. It works with no cooling treatment and also for stationary objects. A sharp response of human body IR radiation was detected with time constants of 3 and 36 sec and radiation responsivity was 3 mAW−1. The current also rises for quite a long time before saturation. This work discusses state-of-the-art material developing technique based on near-infrared photon absorption and their use in field deployable instrument for real-world applications. GO-CNP-based thin solid composite films also offer its potentiality to be utilized as p-type absorber material in thin film solar cell, as well.

  2. Polymer Film-Based Screening and Isolation of Polylactic Acid (PLA)-Degrading Microorganisms.

    Science.gov (United States)

    Kim, Mi Yeon; Kim, Changman; Moon, Jungheun; Heo, Jinhee; Jung, Sokhee P; Kim, Jung Rae

    2017-02-28

    Polylactic acid (PLA) has been highlighted as an alternative renewable polymer for the replacement of petroleum-based plastic materials, and is considered to be biodegradable. On the other hand, the biodegradation of PLA by terminal degraders, such as microorganisms, requires a lengthy period in the natural environment, and its mechanism is not completely understood. PLA biodegradation studies have been conducted using mainly undefined mixed cultures, but only a few bacterial strains have been isolated and examined. For further characterization of PLA biodegradation, in this study, the PLA-degrading bacteria from digester sludge were isolated and identified using a polymer film-based screening method. The enrichment of sludge on PLA granules was conducted with the serial transference of a subculture into fresh media for 40 days, and the attached biofilm was inoculated on a PLA film on an agar plate. 3D optical microscopy showed that the isolates physically degraded the PLA film due to bacterial degradation. 16S rRNA gene sequencing identified the microbial colonies to be Pseudomonas sp. MYK1 and Bacillus sp. MYK2. The two isolates exhibited significantly higher specific gas production rates from PLA biodegradation compared with that of the initial sludge inoculum.

  3. Fabrication and characteristics of magnetic field sensors based on nano-polysilicon thin-film transistors

    International Nuclear Information System (INIS)

    Zhao Xiaofeng; Wen Dianzhong; Zhuang Cuicui; Cao Jingya; Wang Zhiqiang

    2013-01-01

    A magnetic field sensor based on nano-polysilicon thin films transistors (TFTs) with Hall probes is proposed. The magnetic field sensors are fabricated on 〈100〉 orientation high resistivity (ρ > 500 Ω·cm) silicon substrates by using CMOS technology, which adopt nano-polysilicon thin films with thicknesses of 90 nm and heterojunction interfaces between the nano-polysilicon thin films and the high resistivity silicon substrates as the sensing layers. The experimental results show that when V DS = 5.0 V, the magnetic sensitivities of magnetic field sensors based on nano-polysilicon TFTs with length—width ratios of 160 μm/80 μm, 320 μm/80 μm and 480 μm/80 μm are 78 mV/T, 55 mV/T and 34 mV/T, respectively. Under the same conditions, the magnetic sensitivity of the obtained magnetic field sensor is significantly improved in comparison with a Hall magnetic field sensor adopting silicon as the sensing layers. (semiconductor technology)

  4. Anisotropic ferromagnetic behaviors in highly orientated epitaxial NiO-based thin films

    Directory of Open Access Journals (Sweden)

    Yu-Jun Zhang

    2015-07-01

    Full Text Available Antiferromagnetic materials attract a great amount of attention recently for promising antiferromagnet-based spintronics applications. NiO is a conventional antiferromagnetic semiconductor material and can show ferromagnetism by doping other magnetic elements. In this work, we synthesized epitaxial Fe-doped NiO thin films on SrTiO3 substrates with various crystal orientations by pulsed laser deposition. The room-temperature ferromagnetism of these films is anisotropic, including the saturated magnetization and the coercive field. The anisotropic magnetic behaviors of Fe-doped NiO diluted magnetic oxide system should be closely correlated to the magnetic structure of antiferromagnetic NiO base. Within the easy plane of NiO, the coercive field of the films becomes smaller, and larger coercive field while tested out of the easy plane of NiO. The saturated magnetization anisotropy is due to different strain applied by different substrates. These results lead us to more abundant knowledge of the exchange interactions in this conventional antiferromagnetic system.

  5. Electrochemical Biosensor for Nitrite Based on Polyacrylic-Graphene Composite Film with Covalently Immobilized Hemoglobin

    Directory of Open Access Journals (Sweden)

    Raja Zaidatul Akhmar Raja Jamaluddin

    2018-04-01

    Full Text Available A new biosensor for the analysis of nitrite in food was developed based on hemoglobin (Hb covalently immobilized on the succinimide functionalized poly(n-butyl acrylate-graphene [poly(nBA-rGO] composite film deposited on a carbon-paste screen-printed electrode (SPE. The immobilized Hb on the poly(nBA-rGO conducting matrix exhibited electrocatalytic ability for the reduction of nitrite with significant enhancement in the reduction peak at −0.6 V versus Ag/AgCl reference electrode. Thus, direct determination of nitrite can be achieved by monitoring the cathodic peak current signal of the proposed polyacrylic-graphene hybrid film-based voltammetric nitrite biosensor. The nitrite biosensor exhibited a reproducible dynamic linear response range from 0.05–5 mg L−1 nitrite and a detection limit of 0.03 mg L−1. No significant interference was observed by potential interfering ions such as Ca2+, Na+, K+, NH4+, Mg2+, and NO3− ions. Analysis of nitrite in both raw and processed edible bird’s nest (EBN samples demonstrated recovery of close to 100%. The covalent immobilization of Hb on poly(nBA-rGO composite film has improved the performance of the electrochemical nitrite biosensor in terms of broader detection range, lower detection limit, and prolonged biosensor stability.

  6. Graphene oxide/carbon nanoparticle thin film based IR detector: Surface properties and device characterization

    Energy Technology Data Exchange (ETDEWEB)

    Chowdhury, Farzana Aktar [Experimental Physics Division, Atomic Energy Centre, 4, Kazi Nazrul Islam Avenue, Dhaka-1000 (Bangladesh); Hossain, Mohammad Abul [Department of Chemistry, Faculty of Science, University of Dhaka, Dhaka-1000 (Bangladesh); Uchida, Koji; Tamura, Takahiro; Sugawa, Kosuke; Mochida, Tomoaki; Otsuki, Joe [College of Science and Technology, Nihon University, 1-8-14 Kanda Surugadai, Chiyoda-ku, Tokyo 101-8308 (Japan); Mohiuddin, Tariq [Department of Physics, College of Science, Sultan Qaboos University, Muscat (Oman); Boby, Monny Akter [Department of Physics, Faculty of Science, University of Dhaka, Dhaka-1000 (Bangladesh); Alam, Mohammad Sahabul, E-mail: msalam@ksu.edu.sa [Department of Physics, Faculty of Science, University of Dhaka, Dhaka-1000 (Bangladesh); Department of Chemical Engineering, College of Engineering & King Abdullah Institute for Nanotechnology, King Saud University, P.O. Box 2455, Riyadh 11451 (Saudi Arabia)

    2015-10-15

    This work deals with the synthesis, characterization, and application of carbon nanoparticles (CNP) adorned graphene oxide (GO) nanocomposite materials. Here we mainly focus on an emerging topic in modern research field presenting GO-CNP nanocomposite as a infrared (IR) radiation detector device. GO-CNP thin film devices were fabricated from liquid phase at ambient condition where no modifying treatments were necessary. It works with no cooling treatment and also for stationary objects. A sharp response of human body IR radiation was detected with time constants of 3 and 36 sec and radiation responsivity was 3 mAW{sup −1}. The current also rises for quite a long time before saturation. This work discusses state-of-the-art material developing technique based on near-infrared photon absorption and their use in field deployable instrument for real-world applications. GO-CNP-based thin solid composite films also offer its potentiality to be utilized as p-type absorber material in thin film solar cell, as well.

  7. Performance evaluation of symmetric supercapacitor based on cobalt hydroxide [Co(OH)2] thin film electrodes

    International Nuclear Information System (INIS)

    Jagadale, A.D.; Kumbhar, V.S.; Dhawale, D.S.; Lokhande, C.D.

    2013-01-01

    In the present investigation, we have successfully assembled symmetric supercapacitor device based on cobalt hydroxide [Co(OH) 2 ] thin film electrodes using 1 M KOH as an electrolyte. Initially, potentiodynamic electrodeposition method is employed for the preparation of Co(OH) 2 thin films onto stainless steel substrate. These films are characterized for structural and morphological elucidations using X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The XRD reveals formation of β-Co(OH) 2 material with hexagonal crystal structure. The SEM images show formation of nanoflakes like microstructure with average flake width 100 nm. Electrochemical characterizations of Co(OH) 2 based symmetric supercapacitor cell are carried out using cyclic voltammetry, charge–discharge and electrochemical impedance spectroscopy (EIS) techniques. In the performance evaluation the maximum values of specific capacitance, specific energy and specific power are encountered as 44 F g −1 , 3.96 Wh kg −1 and 42 kW kg −1 . The value of equivalent series resistance (ESR) is estimated as 2.3 Ω using EIS

  8. High-mobility pyrene-based semiconductor for organic thin-film transistors.

    Science.gov (United States)

    Cho, Hyunduck; Lee, Sunyoung; Cho, Nam Sung; Jabbour, Ghassan E; Kwak, Jeonghun; Hwang, Do-Hoon; Lee, Changhee

    2013-05-01

    Numerous conjugated oligoacenes and polythiophenes are being heavily studied in the search for high-mobility organic semiconductors. Although many researchers have designed fused aromatic compounds as organic semiconductors for organic thin-film transistors (OTFTs), pyrene-based organic semiconductors with high mobilities and on-off current ratios have not yet been reported. Here, we introduce a new pyrene-based p-type organic semiconductor showing liquid crystal behavior. The thin film characteristics of this material are investigated by varying the substrate temperature during the deposition and the gate dielectric condition using the surface modification with a self-assembled monolayer, and systematically studied in correlation with the performances of transistor devices with this compound. OTFT fabricated under the optimum deposition conditions of this compound, namely, 1,6-bis(5'-octyl-2,2'-bithiophen-5-yl)pyrene (BOBTP) shows a high-performance transistor behavior with a field-effect mobility of 2.1 cm(2) V(-1) s(-1) and an on-off current ratio of 7.6 × 10(6) and enhanced long-term stability compared to the pentacene thin-film transistor.

  9. Miniaturized and reconfigurable notch antenna based on a BST ferroelectric thin film

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Hung Viet [Institut d' Electronique et de Télécommunications de Rennes (IETR), IUT Saint-Brieuc, Université de Rennes 1, 22004 Saint-Brieuc (France); CEA-LETI, Minatec, 17 avenue des Martyrs, 38054 Grenoble Cedex 9 (France); Benzerga, Ratiba, E-mail: ratiba.benzerga@univ-rennes1.fr [Institut d' Electronique et de Télécommunications de Rennes (IETR), IUT Saint-Brieuc, Université de Rennes 1, 22004 Saint-Brieuc (France); Borderon, Caroline [IETR, Université de Nantes, 2 rue de la Houssinière, 44322 Nantes (France); Delaveaud, Christophe [CEA-LETI, Minatec, 17 avenue des Martyrs, 38054 Grenoble Cedex 9 (France); Sharaiha, Ala [Institut d' Electronique et de Télécommunications de Rennes (IETR), IUT Saint-Brieuc, Université de Rennes 1, 22004 Saint-Brieuc (France); Renoud, Raphael [IETR, Université de Nantes, 2 rue de la Houssinière, 44322 Nantes (France); Paven, Claire Le [Institut d' Electronique et de Télécommunications de Rennes (IETR), IUT Saint-Brieuc, Université de Rennes 1, 22004 Saint-Brieuc (France); Pavy, Sabrina; Nadaud, Kevin; Gundel, Hartmut W. [IETR, Université de Nantes, 2 rue de la Houssinière, 44322 Nantes (France)

    2015-07-15

    Highlights: • A miniature and agile antenna based on a BST MIM capacitor is simulated and made. • Mn{sup 2+} doped BST thin films are synthesized by chemical deposition and spin coating. • Permittivity and losses of the BST thin film are respectively 225 and 0.02 at 1 GHz. • A miniaturization rate of 70% is obtained with a MIM capacitance of 3.7 pF. • A frequency tunability of 14.5% and a tunability performance of 0.04 are measured. - Abstract: This work deals with the design, realization and characterization of a miniature and frequency agile antenna based on a ferroelectric Ba{sub 0,80}Sr{sub 0,20}TiO{sub 3} thin film. The notch antenna is loaded with a variable metal/insulator/metal (MIM) capacitor and is achieved by a monolithic method. The MIM capacitance is 3.7 pF, which results in a resonant frequency of 670 MHz compared to 2.25 GHz for the unloaded simulated antenna; the resulting miniaturization rate is 70%. The characterization of the antenna prototype shows a frequency tunable rate of 14.5% under an electric field of 375 kV/cm, with a tunability performance η = 0.04.

  10. Tunable d-Limonene Permeability in Starch-Based Nanocomposite Films Reinforced by Cellulose Nanocrystals.

    Science.gov (United States)

    Liu, Siyuan; Li, Xiaoxi; Chen, Ling; Li, Lin; Li, Bing; Zhu, Jie

    2018-01-31

    In order to control d-limonene permeability, cellulose nanocrystals (CNC) were used to regulate starch-based film multiscale structures. The effect of sphere-like cellulose nanocrystal (CS) and rod-like cellulose nanocrystal (CR) on starch molecular interaction, short-range molecular conformation, crystalline structure, and micro-ordered aggregated region structure were systematically discussed. CNC aspect ratio and content were proved to be independent variables to control d-limonene permeability via film-structure regulation. New hydrogen bonding formation and increased hydroxypropyl starch (HPS) relative crystallinity could be the reason for the lower d-limonene permeability compared with tortuous path model approximation. More hydrogen bonding formation, higher HPS relative crystallinity and larger size of micro-ordered aggregated region in CS0.5 and CR2 could explain the lower d-limonene permeability than CS2 and CR0.5, respectively. This study provided new insight for the control of the flavor release from starch-based films, which favored its application in biodegradable food packaging and flavor encapsulation.

  11. Hydrogenated amorphous silicon sensors based on thin film on ASIC technology

    CERN Document Server

    Despeisse, M; Anelli, G; Jarron, P; Kaplon, J; Rusack, R; Saramad, S; Wyrsch, N

    2006-01-01

    The performance and limitations of a novel detector technology based on the deposition of a thin-film sensor on top of processed integrated circuits have been studied. Hydrogenated amorphous silicon (a-Si:H) films have been deposited on top of CMOS circuits developed for these studies and the resulting "thin-film on ASIC" (TFA) detectors are presented. The leakage current of the a-Si:H sensor at high reverse biases turns out to be an important parameter limiting the performance of a TFA detector. Its detailed study and the pixel segmentation of the detector are presented. High internal electric fields (in the order of 10/sup 4/-10/sup 5/ V/cm) can be built in the a-Si:H sensor and overcome the low mobility of electrons and holes in a-Si:H. Signal induction by generated carrier motion and speed in the a-Si:H sensor have been studied with a 660 nm pulsed laser on a TFA detector based on an ASIC integrating 5 ns peaking time pre- amplifiers. The measurement set-up also permits to study the depletion of the senso...

  12. Flexible pressure sensor based on graphene aerogel microstructures functionalized with CdS nanocrystalline thin film

    Science.gov (United States)

    Plesco, Irina; Dragoman, Mircea; Strobel, Julian; Ghimpu, Lidia; Schütt, Fabian; Dinescu, Adrian; Ursaki, Veaceslav; Kienle, Lorenz; Adelung, Rainer; Tiginyanu, Ion

    2018-05-01

    In this paper, we report on functionalization of graphene aerogel with a CdS thin film deposited by magnetron sputtering and on the development of flexible pressure sensors based on ultra-lightweight CdS-aerogel nanocomposite. Analysis by scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray analysis disclose the uniform deposition of nanocrystalline CdS films with quasi-stoichiometric composition. The piezoresistive response of the aforementioned nanocomposite in the pressure range from 1 to 5 atm is found to be more than one order of magnitude higher than that inherent to suspended graphene membranes, leading to an average sensitivity as high as 3.2 × 10-4 kPa-1.

  13. Development of miniaturized pH biosensors based on electrosynthesized polymer films.

    Science.gov (United States)

    Segut, Olivier; Lakard, Boris; Herlem, Guillaume; Rauch, Jean-Yves; Jeannot, Jean-Claude; Robert, Laurent; Fahys, Bernard

    2007-08-06

    A new type of pH biosensor was developed for biological applications. This biosensor was fabricated using silicon microsystem technology and consists in two platinum microelectrodes. The first microelectrode was coated by an electrosynthesized polymer and acted as the pH sensitive electrode when the second one was coated by a silver layer and was used as the reference electrode. Then, this potentiometric pH miniaturized biosensor based on electrosynthesized polypyrrole or electrosynthesized linear polyethylenimine films was tested. The potentiometric responses appeared reversible and linear to pH changes in the range from pH 4 to 9. More, the responses were fast (less than 1 min for all sensors), they were stable in time since PPy/PEI films were stable during more than 30 days, and no interference was observed. The influence of the polymer thickness was also studied.

  14. Optical Characterization of SERS Substrates Based on Porous Au Films Prepared by Pulsed Laser Deposition

    Directory of Open Access Journals (Sweden)

    V. V. Strelchuk

    2015-01-01

    Full Text Available The SERS (surface enhanced Raman spectroscopy substrates based on nanocomposite porous films with gold nanoparticles (Au NPs arrays were formed using the method of the pulsed laser deposition from the back low-energy flux of erosion torch particles on the glass substrate fixed at the target plain. The dependencies of porosity, and morphology of the surface of the film regions located near and far from the torch axis on the laser ablation regime, laser pulses energy density, their number, and argon pressure in the vacuum chamber, were ascertained. The Au NPs arrays with the controllable extinction spectra caused by the local surface plasmon resonance were prepared. The possibility of the formation of SERS substrates for the detection of the Rhodamine 6G molecules with the concentration 10−10 Mol/L with the enhancement factor 4·107 was shown.

  15. Microstructural evaluation of NiTi-based films deposited by magnetron sputtering

    Energy Technology Data Exchange (ETDEWEB)

    Crăciunescu, Corneliu M., E-mail: corneliu.craciunescu@upt.ro; Mitelea, Ion, E-mail: corneliu.craciunescu@upt.ro; Budău, Victor, E-mail: corneliu.craciunescu@upt.ro [Department of Materials and Manufacturing Engineering, Politehnica University of Timisoara (Romania); Ercuţa, Aurel [Department of Materials and Manufacturing Engineering, Politehnica University of Timisoara and Department of Physics, West University Timisoara (Romania)

    2014-11-24

    Shape memory alloy films belonging to the NiTi-based systems were deposited on heated and unheated substrates, by magnetron sputtering in a custom made system, and their structure and composition was analyzed using electron microscopy. Several substrates were used for the depositions: glass, Cu-Zn-Al, Cu-Al-Ni and Ti-NiCu shape memory alloy ribbons and kapton. The composition of the Ti-Ni-Cu films showed limited differences, compared to the one of the target and the microstructure for the DC magnetron sputtering revealed crystallized structure with features determined on peel off samples from a Si wafer. Both inter and transcrystalline fractures were observed and related to the interfacial stress developed on cooling from deposition temperature.

  16. Pt-based Thin Films as Efficient and Stable Catalysts for Oxygen Electroreduction

    DEFF Research Database (Denmark)

    Zamburlini, Eleonora

    at the cathode of Polymer Electrolyte Membrane Fuel Cells (PEMFCs). Herein the fabrication method, which consists of co-sputtering of thin films, is presented in detail, explaining the challenges one must face in order to fabricate oxygen-free Pt-lanthanides and Pt-early transition metals alloys......This thesis presents the fabrication and characterization of Pt-based thin film catalysts for Oxygen Reduction Reaction (ORR). Gadolinium and Yttrium have been used as alloying materials, in preparation for the replacement of the traditional but economically disadvantageous pure Pt catalysts......, and the proposed solutions. The characterization of the catalysts focused mainly on the electrochemical testing using a Rotating Ring Disk Electrode (RRDE) setup, and includes X-ray Diffraction (XRD), X-ray Photoemission Spectroscopy (XPS), Angle-Resolved X-ray Photoelectron Spectroscopy (AR-XPS), Scanning...

  17. Antimicrobial activity of biodegradable polysaccharide and protein-based films containing active agents.

    Science.gov (United States)

    Kuorwel, Kuorwel K; Cran, Marlene J; Sonneveld, Kees; Miltz, Joseph; Bigger, Stephen W

    2011-04-01

    Significant interest has emerged in the introduction of food packaging materials manufactured from biodegradable polymers that have the potential to reduce the environmental impacts associated with conventional packaging materials. Current technologies in active packaging enable effective antimicrobial (AM) packaging films to be prepared from biodegradable materials that have been modified and/or blended with different compatible materials and/or plasticisers. A wide range of AM films prepared from modified biodegradable materials have the potential to be used for packaging of various food products. This review examines biodegradable polymers derived from polysaccharides and protein-based materials for their potential use in packaging systems designed for the protection of food products from microbial contamination. A comprehensive table that systematically analyses and categorizes much of the current literature in this area is included in the review.

  18. Light illumination effects in ambipolar FETs based on poly(3-hexylthiophene) and fullerene derivative composite films

    International Nuclear Information System (INIS)

    Shibao, Miho; Morita, Takeomi; Takashima, Wataru; Kaneto, Keiichi

    2008-01-01

    The effects of light illumination on field effect transistors based on poly(3-hexylthiophene) (P3HT) and [6,6]-phenyl-C 61 -butyric methyl ester (PCBM) composite films have been studied. It is found that the light illumination on pure P3HT and PCBM generally resulted in decrease of the threshold voltages and increase of the mobilities by a little. In the composite film at the PCBM contents of x = [P3HT] / ([P3HT] + [PCBM]) = 0.67 ∼ 0.9, an ambipolar field transport appeared. The light illumination effect was observed remarkably in the shift of threshold voltage for the hole generation at x = 0.75. Variations of Hole and electron mobilities and threshold voltage of electron generation upon light illumination were basically similar to those of the pure materials. The results were discussed in terms of the light assisted carrier generation in field effects

  19. Portable cholesterol detection with polyaniline-carbon nanotube film based interdigitated electrodes

    International Nuclear Information System (INIS)

    Nguyen, Le Huy; Nguyen, Ngoc Thinh; Nguyen, Hai Binh; Tran, Dai Lam; Nguyen, Tuan Dung

    2012-01-01

    Polyaniline-carboxylic multiwalled carbon nanotubes composite film (PANi-MWCNT) has been polymerized on the surface of interdigitated platinum electrode (fabricated by MEMS technology) which was compatibly connected to Autolab interface via universal serial bus (USB). An amperometric biosensor based on covalent immobilization of cholesterol oxidase (ChOx) on PANi–MWCNT film with potassium ferricyanide (FeCN) as the redox mediator was developed. The mediator helps to shuttle the electrons between the immobilized ChOx and the PANi-MWCNT electrode, therefore operating at a low potential of −0.3 V compared to the saturated calomel electrode (SCE). This potential precludes the interfering compounds from oxidization. The bio-electrode exhibits good linearity from 0.02 to 1.2 mM cholesterol concentration with a correlation coefficient of 0.9985

  20. Transparent films based on PLA and montmorillonite with tunable oxygen barrier properties

    DEFF Research Database (Denmark)

    Svagan, Anna; Åkesson, Anna; Cárdenas, Marité

    2012-01-01

    Polylactide (PLA) is viewed as a potential material to replace synthetic plastics (e.g., poly(ethylene terephthalate) (PET)) in food packaging, and there have been a number of developments in this direction. However, for PLA to be competitive in more demanding uses such as the packaging of oxygen......-sensitive foods, the oxygen permeability coefficient (OP) needs to be reduced by a factor of ∼10. To achieve this, a layer-by-layer (Lbl) approach was used to assemble alternating layers of montmorillonite clay and chitosan on extruded PLA film surfaces. When 70 bilayers were applied, the OP was reduced by 99...... and 96%, respectively, at 20 and 50% RH. These are, to our knowledge, the best improvements in oxygen barrier properties ever reported for a PLA/clay-based film. The process of assembling such multilayer structures was characterized using a quartz crystal microbalance with dissipation monitoring...

  1. Influence of Heat Treatment on the Morphologies of Copper Nanoparticles Based Films by a Spin Coating Method

    Directory of Open Access Journals (Sweden)

    Wei Liu

    2017-01-01

    Full Text Available We have investigated the influence of heat treatment on the morphologies of copper nanoparticles based films on glass slides by a spin coating method. The experiments show that heat treatment can modify the sizes and morphologies of copper nanoparticles based films on glass slides. We suggest that through changing the parameters of heat treatment process may be helpful to vary the scattering and absorbing intensity of copper nanoparticles when used in energy harvesting/conversion and optical devices.

  2. Dielectric and piezoelectric properties of lead-free (Bi,Na)TiO3-based thin films

    Science.gov (United States)

    Abazari, M.; Safari, A.; Bharadwaja, S. S. N.; Trolier-McKinstry, S.

    2010-02-01

    Dielectric and piezoelectric properties of morphotropic phase boundary (Bi,Na)TiO3-(Bi,K)TiO3-BaTiO3 epitaxial thin films deposited on SrRuO3 coated SrTiO3 substrates were reported. Thin films of 350 nm thickness exhibited small signal dielectric permittivity and loss tangent values of 750 and 0.15, respectively, at 1 kHz. Ferroelectric hysteresis measurements indicated a remanent polarization value of 30 μC/cm2 with a coercive field of 85-100 kV/cm. The thin film transverse piezoelectric coefficient (e31,f) of these films after poling at 600 kV/cm was found to be -2.2 C/m2. The results indicate that these BNT-based thin films are a potential candidate for lead-free piezoelectric devices.

  3. Analytical prediction of CHF by FIDAS code based on three-fluid and film-dryout model

    International Nuclear Information System (INIS)

    Sugawara, Satoru

    1990-01-01

    Analytical prediction model of critical heat flux (CHF) has been developed on the basis of film dryout criterion due to droplets deposition and entrainment in annular mist flow. Critical heat flux in round tubes were analyzed by the Film Dryout Analysis Code in Subchannels (FIDAS) which is based on the three-fluid, three-field and newly developed film dryout model. Predictions by FIDAS were compared with the world-wide experimental data on CHF obtained in water and Freon for uniformly and non-uniformly heated tubes under vertical upward flow condition. Furthermore, CHF prediction capability of FIDAS was compared with those of other film dryout models for annular flow and Katto's CHF correlation. The predictions of FIDAS are in sufficient agreement with the experimental CHF data, and indicate better agreement than the other film dryout models and empirical correlation of Katto. (author)

  4. An ultrathin wide-band planar metamaterial absorber based on a fractal frequency selective surface and resistive film

    International Nuclear Information System (INIS)

    Fan Yue-Nong; Cheng Yong-Zhi; Nie Yan; Wang Xian; Gong Rong-Zhou

    2013-01-01

    We propose an ultrathin wide-band metamaterial absorber (MA) based on a Minkowski (MIK) fractal frequency selective surface and resistive film. This absorber consists of a periodic arrangement of dielectric substrates sandwiched with an MIK fractal loop structure electric resonator and a resistive film. The finite element method is used to simulate and analyze the absorption of the MA. Compared with the MA-backed copper film, the designed MA-backed resistive film exhibits an absorption of 90% at a frequency region of 2 GHz–20 GHz. The power loss density distribution of the MA is further illustrated to explain the mechanism of the proposed MA. Simulated absorptions at different incidence cases indicate that this absorber is polarization-insensitive and wide-angled. Finally, further simulated results indicate that the surface resistance of the resistive film and the dielectric constant of the substrate can affect the absorbing property of the MA. This absorber may be used in many military fields

  5. Chitosan-based films composites for wound healing purposes; Filmes compositos de quitosana para aplicacao no revestimento de ferimentos

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Natali de O.; Silva, Gabriela T. da; Schulz, Gracelie A.S.; Fajardo, Andre R., E-mail: natalioliveiraalves@gmail.com [Universidade Federal de Pelotas (LaCoPol/UFPel), Pelotas, RS (Brazil). Centro de Ciencias Quimicas, Farmaceuticas e de Alimentos. Lab. de Tecnologia e Desenvolvimento de Compositos e Materiais Polimericos

    2015-07-01

    Chitosan has been extensively applied in the developing of biomaterials due to its desirable good physico-chemical and biological properties. According to this, here films composite of chitosan, poly(vinyl alcohol) and bovine bone powder were prepared by casting willing to be applied in wound healing purposes. Moreover, the first step was the developing of a suitable method to obtain bovine bone powder, which was utilized here as filler. All the materials and films were fully characterized by FTIR, DRX and thermal analysis. Water uptake capacity was measured by swelling assays. (author)

  6. Critical current density measurement of thin films by AC susceptibility based on the penetration parameter h

    DEFF Research Database (Denmark)

    Li, Xiao-Fen; Grivel, Jean-Claude; Abrahamsen, Asger B.

    2012-01-01

    We have numerically proved that the dependence of AC susceptibility χ of a E(J) power law superconducting thin disc on many parameters can be reduced to one penetration parameter h, with E the electric field and J the current density. Based on this result, we propose a way of measuring the critical...... current density Jc of superconducting thin films by AC susceptibility. Compared with the normally used method based on the peak of the imaginary part, our method uses a much larger range of the AC susceptibility curve, thus allowing determination of the temperature (T) dependence of Jc from a normally...

  7. Dithienocoronenediimide-based copolymers as novel ambipolar semiconductors for organic thin-film transistors.

    Science.gov (United States)

    Usta, Hakan; Newman, Christopher; Chen, Zhihua; Facchetti, Antonio

    2012-07-17

    A new class of ambipolar donor-acceptor π-conjugated polymers based on a dithienocoronenediimide core is presented. Solution-processed top-gate/bottom-contact thin film transistors (TFTs) exhibit electron and hole mobilities of up to 0.30 cm(2)/V·s and 0.04 cm(2)/V·s, respectively, which are the highest reported to date for an ambipolar polymer in ambient conditions. The polymers presented here are the first examples of coronenediimide-based semiconductors showing high organic TFT performances. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  8. Indirect potentiometric titration of ascorbic acid in pharmaceutical preparations using copper based mercury film electrode.

    Science.gov (United States)

    Abdul Kamal Nazer, Meeran Mohideen; Hameed, Abdul Rahman Shahul; Riyazuddin, Patel

    2004-01-01

    A simple and rapid potentiometric method for the estimation of ascorbic acid in pharmaceutical dosage forms has been developed. The method is based on treating ascorbic acid with iodine and titration of the iodide produced equivalent to ascorbic acid with silver nitrate using Copper Based Mercury Film Electrode (CBMFE) as an indicator electrode. Interference study was carried to check possible interference of usual excipients and other vitamins. The precision and accuracy of the method was assessed by the application of lack-of-fit test and other statistical methods. The results of the proposed method and British Pharmacopoeia method were compared using F and t-statistical tests of significance.

  9. Effect of lipid-based dry eye supplements on the tear film in wearers of eye cosmetics.

    Science.gov (United States)

    Wang, Michael T M; Cho, Irene Sung Hee; Jung, Soo Hee; Craig, Jennifer P

    2017-08-01

    To compare the effects on tear film parameters and contamination in cosmetic eyeliner wearers, after single application of two lipid-based dry eye treatments: a lipid-containing lubricant eye drop and a phospholipid liposomal spray. Fifty participants were enrolled in a prospective, randomised, paired-eye, investigator-masked trial. Pencil eyeliner (Body Shop ® Crayon Eye Definer) was applied to the upper eyelid periocular skin of both eyes, anterior to the lash line. Baseline tear film quality was assessed fifteen minutes after eyeliner application. A lubricant drop (Systane ® Balance) was then applied to one eye (randomised), and liposomal spray (Tears Again ® ) to the contralateral eye. Tear film contamination, lipid layer grade, non-invasive tear film break-up time and tear evaporation rate were evaluated fifteen minutes post-treatment and compared to pre-treatment values. Pre-treatment measurements did not differ between eyes assigned to lubricant drop and liposomal spray. Tear film contamination was observed in a greater proportion of eyes following both treatments (both p0.05). Changes in tear film parameters did not differ between treatments (all p>0.05). Both the lipid-containing lubricant eye drop and phospholipid liposomal spray result in clinically apparent tear film contamination in eyeliner cosmetic wearers. Although both treatments effected an increase in lipid layer thickness, neither displayed clinical efficacy in improving tear film stability. Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

  10. Preparation and characterization of chitosan-based antimicrobial active food packaging film incorporated with apple peel polyphenols.

    Science.gov (United States)

    Riaz, Asad; Lei, Shicheng; Akhtar, Hafiz Muhammad Saleem; Wan, Peng; Chen, Dan; Jabbar, Saqib; Abid, Muhammad; Hashim, Malik Muhammad; Zeng, Xiaoxiong

    2018-07-15

    In the present study, apple peel polyphenols (APP) were incorporated into chitosan (CS) to develop a novel functional film. Scanning electron microscopy, Fourier transform-infrared spectroscopy and thermogravimetric analyses were performed to study the structure, potential interaction and thermal stability of the prepared films. Physical properties including moisture content, density, color, opacity, water solubility, swelling ration and water vapor permeability were measured. The results revealed that addition of APP into CS significantly improved the physical properties of the film by increasing its thickness, density, solubility, opacity and swelling ratio whereas moisture content and water vapor permeability were decreased. Tensile strength and elongation at break of the CS-APP film with 1% APP was 16.48MPa and 13.33%, respectively, significantly lower than those for CS control film. Thermal stability of the prepared films was decreased while antioxidant and antimicrobial activities of the CS-based APP film were significantly increased. CS-APP film with 0.50% APP concentration exhibited good mechanical and antimicrobial properties, indicating that it could be developed as bio-composite food packaging material for the food industry. Copyright © 2018 Elsevier B.V. All rights reserved.

  11. A study of graphene films synthesized on nickel substrates: existence and origin of small-base-area peaks

    International Nuclear Information System (INIS)

    Kahng, Yung Ho; Choe, Minhyeok; Jo, Gunho; Park, Woojin; Yoon, Jongwon; Hong, Woong-Ki; Lee, Byoung Hun; Lee, Takhee; Lee, Sangchul; Cho, Chun Hum

    2011-01-01

    Large-area graphene films, synthesized by the chemical vapor deposition (CVD) method, have the potential to be used as electrodes. However, the electrical properties of CVD-synthesized graphene films fall short of the best results obtained for graphene films prepared by other methods. Therefore, it is important to understand the reason why these electrical properties are inferior to improve the applicability of CVD-grown graphene films. Here, we show that CVD-grown graphene films on nickel substrates contain many small-base-area (SBA) peaks that scatter conducting electrons, thereby decreasing the Hall mobility of charges in the films. These SBA peaks were induced by small peaks on the nickel surface and are likely composed of amorphous carbon. The formation of these SBA peaks on graphene films was successfully suppressed by controlling the surface morphology of the nickel substrate. These findings may be useful for the development of a CVD synthesis method that is capable of producing better quality graphene films with large areas.

  12. Polyox and carrageenan based composite film dressing containing anti-microbial and anti-inflammatory drugs for effective wound healing.

    Science.gov (United States)

    Boateng, Joshua S; Pawar, Harshavardhan V; Tetteh, John

    2013-01-30

    Polyethylene oxide (Polyox) and carrageenan based solvent cast films have been formulated as dressings for drug delivery to wounds. Films plasticised with glycerol were loaded with streptomycin (30%, w/w) and diclofenac (10%, w/w) for enhanced healing effects in chronic wounds. Blank and drug loaded films were characterised by texture analysis (for mechanical and mucoadhesive properties), scanning electron microscopy, differential scanning calorimetry, X-ray diffraction and Fourier transform infrared spectroscopy. In addition, swelling, in vitro drug release and antibacterial studies were conducted to further characterise the films. Both blank and drug loaded films showed a smooth, homogeneous surface morphology, excellent transparency, high elasticity and acceptable tensile (mechanical) properties. The drug loaded films showed a high capacity to absorb simulated wound fluid and significant mucoadhesion force which is expected to allow effective adherence to and protection of the wound. The films showed controlled release of both streptomycin and diclofenac for 72 h. These drug loaded films produced higher zones of inhibition against Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli compared to the individual drugs zones of inhibition. Incorporation of streptomycin can prevent and treat chronic wound infections whereas diclofenac can target the inflammatory phase of wound healing to relieve pain and swelling. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. Mechanical and barrier properties of starch-based films plasticized with two- or three component deep eutectic solvents.

    Science.gov (United States)

    Zdanowicz, Magdalena; Johansson, Caisa

    2016-10-20

    The aim of this work was to prepare two- and three-components deep eutectic solvents (DES) and investigate their potential as starch plasticizers. Starch/DES films were prepared via casting method. Mechanical properties, water vapor- and oxygen transmission rates were measured; additionally contact angle and moisture sorption were determined and FTIR analysis was applied on the films. Native potato starch and hydroxypropylated and oxidized starch (HOPS) with common plasticizers (e.g. polyols, urea) and DES were studied. Moreover, influence of three methods of DES introduction and concentration of plasticizer on the films properties were compared. HOPS films were prepared by two methods: as non-cured and cured samples. Some of DESs containing citrate anion exhibited crosslinking ability of polysaccharide matrix. Non-cured HOPS/DES films exhibited more favourable mechanical and barrier properties than cured analogue films. Samples prepared with unmodified potato starch had higher mechanical and barrier properties than films made with HOPS. Starch-based films plasticized with novel DESs with parallel crosslinking activity exhibited satisfactory mechanical and barrier properties. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Layered Cu-based electrode for high-dielectric constant oxide thin film-based devices

    International Nuclear Information System (INIS)

    Fan, W.; Saha, S.; Carlisle, J.A.; Auciello, O.; Chang, R.P.H.; Ramesh, R.

    2003-01-01

    Ti-Al/Cu/Ta multilayered electrodes were fabricated on SiO 2 /Si substrates by ion beam sputtering deposition, to overcome the problems of Cu diffusion and oxidation encountered during the high dielectric constant (κ) materials integration. The Cu and Ta layers remained intact through the annealing in oxygen environment up to 600 deg. C. The thin oxide layer, formed on the Ti-Al surface, effectively prevented the oxygen penetration toward underneath layers. Complex oxide (Ba x Sr 1-x )TiO 3 (BST) thin films were grown on the layered Ti-Al/Cu/Ta electrodes using rf magnetron sputtering. The deposited BST films exhibited relatively high permittivity (150), low dielectric loss (0.007) at zero bias, and low leakage current -8 A/cm 2 at 100 kV/cm

  15. Finite element analysis of displacement actuator based on giant magnetostrictive thin film

    Directory of Open Access Journals (Sweden)

    Shaopeng Yu

    2018-05-01

    Full Text Available With the rapid development of science and technology, mechanical and electrical equipment become more and more miniature. In order to achieve precise control in less than 1cm3, the giant magnetostrictive thin film has become a research hotspot. The micro displacement actuator with planar and arc film is designed by the dynamic coupling model based on J-A model and magneto-mechanical effect method which is proposed in this paper. The different structure and thickness of films are analyzed by COMSOL Multiphysics software when the current flows through driving coil. After comparing the simulation results with the test ones, it can be seen that the coupling model is accurate and the structure is reliable. At the same time, MATLAB is used to fit the current density-displacement curve and higher order equation is obtained, and then the feasibility of design can be verified. The actuator with arc structure had advantages of small volume, fast response, high precision, easy integration, etc., which has a broad application prospect in the field of vibration control, micro positioning, robot and so on.

  16. Natamycin based sol-gel antimicrobial coatings on polylactic acid films for food packaging.

    Science.gov (United States)

    Lantano, Claudia; Alfieri, Ilaria; Cavazza, Antonella; Corradini, Claudio; Lorenzi, Andrea; Zucchetto, Nicola; Montenero, Angelo

    2014-12-15

    In this work a comprehensive study on a new active packaging obtained by a hybrid organic-inorganic coating with antimicrobial properties was carried out. The packaging system based on polylactic acid was realised by sol-gel processing, employing tetraethoxysilane as a precursor of the inorganic phase and polyvinyl alcohol as the organic component, and incorporating natamycin as the active agent. Films with different organic-inorganic ratios (in a range between 1:19 and 1:4) were prepared, and the amount of antimycotic entrapped was found to be modulated by the sol composition, and was between 0.18 and 0.25mg/dm(2). FTIR microspectroscopic measurements were used to characterise the prepared coatings. The antifungal properties of the films were investigated against mould growth on the surface of commercial semi-soft cheese. The release of natamycin from the films to ethanol 50% (v/v) was studied by means of HPLC UV-DAD. The maximal level released was about 0.105 mg/dm(2), which is far below the value allowed by legislation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  17. Radon-film-badges by solid radiators to complement track detector-based radon monitors

    International Nuclear Information System (INIS)

    Tommasino, L.; Tommasino, M.C.; Viola, P.

    2009-01-01

    Existing passive radon monitors, based on track detectors, present many shortcomings, such as a limited response sensitivity for one-week-indoor measurements and a limited response linearity for the assessment of large radon exposures indoors, in thermal spa, in caves, and in soil. Moreover, for in-soil measurements these monitors are too bulky and are often conducive to wrong results. For what concerns the radon-in-water measurements, they are just not suitable. A new generation of passive radon monitors is introduced in this paper, which are very similar to the compact badges used in neutron- and gamma-dosimetry and will be referred to as radon-film-badges. These film-badges are formed by thin-film radiators with suitable radon-sorption characteristics, facing track detectors. The key strategy adopted for these radiators is to exploit an equilibrium type of radon sorption in solids. Even though this new generation of passive monitors is at its infancy, it appears already clear that said monitors make it finally possible to overcome most of the shortcomings of existing passive radon monitors. These devices are uniquely simple and can be easily acquired by any existing radon service to complement their presently used passive radon monitors with little or no effort.

  18. Finite element analysis of displacement actuator based on giant magnetostrictive thin film

    Science.gov (United States)

    Yu, Shaopeng; Wang, Bowen; Zhang, Changgeng; Cui, Baozhi

    2018-05-01

    With the rapid development of science and technology, mechanical and electrical equipment become more and more miniature. In order to achieve precise control in less than 1cm3, the giant magnetostrictive thin film has become a research hotspot. The micro displacement actuator with planar and arc film is designed by the dynamic coupling model based on J-A model and magneto-mechanical effect method which is proposed in this paper. The different structure and thickness of films are analyzed by COMSOL Multiphysics software when the current flows through driving coil. After comparing the simulation results with the test ones, it can be seen that the coupling model is accurate and the structure is reliable. At the same time, MATLAB is used to fit the current density-displacement curve and higher order equation is obtained, and then the feasibility of design can be verified. The actuator with arc structure had advantages of small volume, fast response, high precision, easy integration, etc., which has a broad application prospect in the field of vibration control, micro positioning, robot and so on.

  19. Coupled Simulation of Thermomagnetic Energy Generation Based on NiMnGa Heusler Alloy Films

    Science.gov (United States)

    Kohl, Manfred; Gueltig, Marcel; Wendler, Frank

    2018-03-01

    This paper presents a simulation model for the coupled dynamic properties of thermomagnetic generators based on magnetic shape memory alloy (MSMA) films. MSMA thermomagnetic generators exploit the large abrupt temperature-induced change of magnetization at the first- or second-order magnetic transition as well as the short heat transfer times due to the large surface-to-volume ratio of films. These properties allow for resonant self-actuation of freely movable MSMA cantilever devices showing thermomagnetic duty cycles in the order of 10 ms duration, which matches with the period of oscillatory motion. We present a numerical analysis of the energy conversion processes to understand the effect of design parameters on efficiency and power output. A lumped element model is chosen to describe the time dependence of MSMA cantilever deflection and of temperature profiles as well as the magnitude and phase dependency of magnetization change. The simulation model quantitatively describes experimentally observed oscillatory motion and resulting power output in the order of 100 mW cm-3. Furthermore, it predicts a power output of 490 mW cm-3 for advanced film materials with temperature-dependent change of magnetization Δ M/Δ T of 4 A m2 (kg K)-1, which challenges state-of-the-art thermoelectric devices.

  20. Structural and optical properties of arsenic sulfide films synthesized by a novel PECVD-based approach

    Science.gov (United States)

    Mochalov, Leonid; Kudryashov, Mikhail; Logunov, Aleksandr; Zelentsov, Sergey; Nezhdanov, Aleksey; Mashin, Alexandr; Gogova, Daniela; Chidichimo, Giuseppe; De Filpo, Giovanni

    2017-11-01

    A new plasma-enhanced chemical vapor deposition-based (PECVD) approach for synthesizing of As-S films, with As content in the range 60-40 at.%, is demonstrated. The process has been carried out in a low-temperature Ar-plasma, employing for the first time volatile As and S as precursors. Utilization of inorganic elemental precursors, in contrast to the typically used in CVD metal-organic compounds or volatile hydrides/halides of Va- and VIa-group-elements, gives the possibility to reach the highest quality and purity of the As-S ≿halcogenide films. Quantum-chemical calculations have been performed to gain insight into the PECVD As-S chalcogenide films structure and the mechanism of its formation in the plasma discharge. An additional vibrational band near 650 cm-1 corresponding to cycled 2-dimensional units is observed by Raman spectroscopy. The process developed is cost-efficient one due to the very precise control and the long-term stability of the plasma parameters and it possesses a high potential for large-area applications such as fabrication of miniature integrated optical elements and 2D/3D printing of optical devices.

  1. Chemical vapor deposition based tungsten disulfide (WS2) thin film transistor

    KAUST Repository

    Hussain, Aftab M.

    2013-04-01

    Tungsten disulfide (WS2) is a layered transition metal dichalcogenide with a reported band gap of 1.8 eV in bulk and 1.32-1.4 eV in its thin film form. 2D atomic layers of metal dichalcogenides have shown changes in conductivity with applied electric field. This makes them an interesting option for channel material in field effect transistors (FETs). Therefore, we show a highly manufacturable chemical vapor deposition (CVD) based simple process to grow WS2 directly on silicon oxide in a furnace and then its transistor action with back gated device with room temperature field effect mobility of 0.1003 cm2/V-s using the Schottky barrier contact model. We also show the semiconducting behavior of this WS2 thin film which is more promising than thermally unstable organic materials for thin film transistor application. Our direct growth method on silicon oxide also holds interesting opportunities for macro-electronics applications. © 2013 IEEE.

  2. Photo-sensitive Ge nanocrystal based films controlled by substrate deposition temperature

    Science.gov (United States)

    Stavarache, Ionel; Maraloiu, Valentin Adrian; Negrila, Catalin; Prepelita, Petronela; Gruia, Ion; Iordache, Gheorghe

    2017-10-01

    Lowering the temperature of crystallization by deposition of thin films on a heated substrate represents the easiest way to find new means to develop and improve new working devices based on nanocrystals embedded in thin films. The improvements are strongly related with the increasing of operation speed, substantially decreasing the energy consumption and reducing unit fabrication costs of the respective semiconductor devices. This approach avoids major problems, such as those related to diffusion or difficulties in controlling nanocrystallites size, which appear during thermal treatments at high temperatures after deposition. This article reports on a significant progress given by structuring Ge nanocrystals (Ge-NCs) embedded in silicon dioxide (SiO2) thin films by heating the substrate at 400 °C during co-deposition of Ge and SiO2 by magnetron sputtering. As a proof-of-concept, a Si/Ge-NCs:SiO2 photo-sensitive structure was fabricated thereof and characterized. The structure shows superior performance on broad operation bandwidth from visible to near-infrared, as strong rectification properties in dark, significant current rise in the inversion mode when illuminated, high responsivity, high photo-detectivity of 1014 Jones, quick response and significant conversion efficiency with peak value reaching 850% at -1 V and about 1000 nm. This simple preparation approach brings an important contribution to the effort of structuring Ge nanocrystallites in SiO2 thin films at a lower temperature for the purpose of using these materials for devices in optoelectronics, solar cells and electronics on flexible substrates.

  3. Photo-sensitive Ge nanocrystal based films controlled by substrate deposition temperature

    KAUST Repository

    Stavarache, Ionel

    2017-07-21

    Lowering the temperature of crystallization by deposition of thin films on a heated substrate represents the easiest way to find new means to develop and improve new working devices based on nanocrystals embedded in thin films. The improvements are strongly related with the increasing of operation speed, substantially decreasing the energy consumption and reducing unit fabrication costs of the respective semiconductor devices. This approach avoids major problems, such as those related to diffusion or difficulties in controlling of nanocrystallites size, which appear during thermal treatments at high temperatures after deposition. It is reported here the significant progress introduced by synthesis procedure to the in-situ structuring of Ge nanocrystallites in SiO2 thin films by heating the substrate at low temperature, 400 °C during co-deposition of Ge and SiO2 by magnetron sputtering. As a proof-of-concept, a Si/Ge-NCs:SiO2 photo-sensitive structure was fabricated thereof and characterized. The structure shows superior performance on broad operation bandwidth from visible to near-infrared, as strong rectification properties in dark, significant current rise in the inversion mode when illuminated, high responsivity, high photo-detectivity of 1014 Jones, quick response and significant conversion efficiency of 850 %. This simple preparation approach brings an important contribution to the efort of structuring Ge nanocrystallites in SiO2 thin films at a lower temperature for the purpose of using these materials for devices in optoelectronics, solar cells and electronics on flexible substrates.

  4. Characteristic study of chitosan addition in Tilapia (Oreochromis niloticus) bone based gelatin film

    Science.gov (United States)

    Atmaka, W.; Yudhistira, B.; Putro, M. I. S.

    2018-03-01

    Tilapia (Oreochromis niloticus) is one of popular fish species in Indonesia. The high number in tilapia’s production and export of tilapia resulting in the increase of bone fish waste. an attempt to decrease the amount of the aforementioned waste, the fish bones were turned into gelatine. The gelatine produced from this waste can be put to good use by turning it into edible film due to its high water resistance and low tensile strength value. However, in order to make a proper film, both the water resistance and the tensile strength value needs another appropriate additional biopolymer. In this case, the appropriate biopolymer needed both to form the film and to repair its characteristics is chitosan. The purpose of this research is to find out the effect of the chitosan addition on the tilapia bone based gelatine film. The research used several mixtures of gelatine (G) and chitosan (C) with the following ratio: G100:C0 (GC1), G75:C25 (GC2), G50:C50 (GC3), G25:C75 (GC4), G0:C100 (GC5). ANOVA results (Psolubility, tensile strength, elongation at break, Fourier Transform Infrared (FTIR), color a, and color b but no significant effects on the vapor permeability and color L. The best result is shown on GC2 with thickness 0.119 mm; solubility 74.95%; tensile strength 2.635 Mpa; elongation at break 68.26%; water vapor permeability 5.897 g/h m2 and FTIR. The parameters in GC2 shows good compatibility between the two biopolymers.

  5. Composite films based on biorelated agro-industrial waste and poly(vinyl alcohol). Preparation and mechanical properties characterization.

    Science.gov (United States)

    Chiellini, E; Cinelli, P; Imam, S H; Mao, L

    2001-01-01

    As a part of an ongoing project on the production of composite materials based on poly(vinyl alcohol) (PVA) and polymeric materials from renewable resources, the present paper reports on the incorporation of agricultural waste materials as organic fillers in a film matrix based on PVA as continuous phase. In this study lignocellulosic fibers byproducts, derived from sugar cane (SC) and apple (AP) and orange (OR) fruit juice extraction, were cast from PVA aqueous solutions. The effect of fiber type and composition on the relative properties of cast films was evaluated and compared. OR resulted to be suitable for blending in higher amounts by weight than SC and AP. Glycerol and urea were added as plasticizing agents and were observed to be effective in giving flexible films. Additionally, cornstarch was added to further increase the composition of polymers from renewable resources in cost-effective and ecoefficient composite film formulations. The prepared films resulted sensitive to moisture and water. To reduce water sensitivity, hexamethoxymethylmelamine (HMMM) was tested as a cross-linking agent for the present composite formulations. Cross-linked films exhibited significant improvement in water-resistance that can be taken as a tuneable structural feature for customized applications. The mechanical properties of the prepared composite films (elongation at break, tensile strength, Young modulus) were found to be dependent upon the nature and content of the filler and on environmental conditions.

  6. Hydrogen effects on deep level defects in proton implanted Cu(In,Ga)Se{sub 2} based thin films

    Energy Technology Data Exchange (ETDEWEB)

    Lee, D.W.; Seol, M.S.; Kwak, D.W.; Oh, J.S. [Department of Physics, Dongguk University, Seoul 100-715 (Korea, Republic of); Jeong, J.H. [Photo-electronic Hybrids Research Center, Korea Institute of Science and Technology, Seoul 136-791 (Korea, Republic of); Cho, H.Y., E-mail: hycho@dongguk.edu [Department of Physics, Dongguk University, Seoul 100-715 (Korea, Republic of)

    2012-08-01

    Hydrogen effects on deep level defects and a defect generation in proton implanted Cu(In,Ga)Se{sub 2} (CIGS) based thin films for solar cell were investigated. CIGS films with a thickness of 3 {mu}m were grown on a soda-lime glass substrate by a co-evaporation method, and then were implanted with protons. To study deep level defects in the proton implanted CIGS films, deep level transient spectroscopy measurements on the CIGS-based solar cells were carried out, these measurements found 6 traps (including 3 hole traps and 3 electron traps). In the proton implanted CIGS films, the deep level defects, which are attributed to the recombination centers of the CIGS solar cell, were significantly reduced in intensity, while a deep level defect was generated around 0.28 eV above the valence band maximum. Therefore, we suggest that most deep level defects in CIGS films can be controlled by hydrogen effects. - Highlights: Black-Right-Pointing-Pointer Proton implanted Cu(In,Ga)Se{sub 2} thin film and solar cell are prepared. Black-Right-Pointing-Pointer Deep level defects of Cu(In,Ga)Se{sub 2} thin film and solar cell are investigated. Black-Right-Pointing-Pointer Hydrogenation using proton implantation and H{sub 2} annealing reduces deep level defects. Black-Right-Pointing-Pointer Hydrogenation could enhance electrical properties and efficiency of solar cells.

  7. Thermochromic Oxide-Based Thin Films and Nanoparticle Composites for Energy-Efficient Glazings

    Directory of Open Access Journals (Sweden)

    Claes G. Granqvist

    2016-12-01

    Full Text Available Today’s advances in materials science and technology can lead to better buildings with improved energy efficiency and indoor conditions. Particular attention should be directed towards windows and glass facades—jointly known as “glazings”—since current practices often lead to huge energy expenditures related to excessive inflow or outflow of energy which need to be balanced by energy-intensive cooling or heating. This review article outlines recent progress in thermochromics, i.e., it deals with materials whose optical properties are strongly dependent on temperature. In particular, we discuss oxide-based thin surface coatings (thin films and nanoparticle composites which can be deposited onto glass and are able to regulate the throughput of solar energy while the luminous (visible properties remain more or less unaltered. Another implementation embodies lamination materials incorporating thermochromic (TC nanoparticles. The thin films and nanocomposites are based on vanadium dioxide (VO2, which is able to change its properties within a narrow temperature range in the vicinity of room temperature and either reflects or absorbs infrared light at elevated temperatures, whereas the reflectance or absorptance is much smaller at lower temperatures. The review outlines the state of the art for these thin films and nanocomposites with particular attention to recent developments that have taken place in laboratories worldwide. Specifically, we first set the scene by discussing environmental challenges and their relationship with TC glazings. Then enters VO2 and we present its key properties in thin-film form and as nanoparticles. The next part of the article gives perspectives on the manufacturing of these films and particles. We point out that the properties of pure VO2 may not be fully adequate for buildings and we elaborate how additives, antireflection layers, nanostructuring and protective over-coatings can be employed to yield improved

  8. Achieving a Collapsible, Strong, and Highly Thermally Conductive Film Based on Oriented Functionalized Boron Nitride Nanosheets and Cellulose Nanofiber.

    Science.gov (United States)

    Wu, Kai; Fang, Jinchao; Ma, Jinrui; Huang, Rui; Chai, Songgang; Chen, Feng; Fu, Qiang

    2017-09-06

    Boron nitride nanosheet (BNNS) films receive wide attention in both academia and industry because of their high thermal conductivity (TC) and good electrical insulation capability. However, the brittleness and low strength of the BNNS film largely limit its application. Herein, functionalized BNNSs (f-BNNSs) with a well-maintained in-plane crystalline structure were first prepared utilizing urea in the aqueous solution via ball-milling for the purpose of improving their stability in water and enhancing the interaction with the polymer matrix. Then, a biodegradable and highly thermally conductive film with an orderly oriented structure based on cellulose nanofibers (CNFs) and f-BNNSs was prepared just by simple vacuum-assisted filtration. The modification of the BNNS and the introduction of the CNF result in a better orientation of the f-BNNS, sufficient connection between f-BNNS themselves, and strong interaction between f-BNNS and CNF, which not only make the prepared composite film strong and tough but also possess higher in-plane TC. An increase of 70% in-plane TC, 63.2% tensile strength, and 77.8% elongation could be achieved for CNF/f-BNNS films, compared with that for CNF/BNNS films at the filler content of 70%. Although at such a high f-BNNS content, this composite film can be bended and folded. It is even more interesting to find that the in-plane TC could be greatly enhanced with the decrease of the thickness of the film, and a value of 30.25 W/m K can be achieved at the thickness of ∼30 μm for the film containing 70 wt % f-BNNS. We believe that this highly thermally conductive film with good strength and toughness could have potential applications in next-generation highly powerful and collapsible electronic devices.

  9. Integrated-circuit microwave detector based on granular high-Tc thin films. [Y-Ba-Cu-O

    Energy Technology Data Exchange (ETDEWEB)

    Drobinin, A.V.; Lutovinov, V.S.; Starostenko, I.V. (Moscow Inst. of Radioengineering, Electronics and Automation, (MIREA), Moscow (USSR))

    1991-12-01

    A highly sensitive integrative-circuit microwave detector based on granular High-Tc film has been designed. All matching circuits and High-Tc microbridge are located on the same substrate. The voltage responsivity 10{sup 3} V/W has been found at 65 K and frequency 5 GHz. Different modes of microwave detection have been observed: bolometric response near Tc in high-quality films, rectification mode caused by an array of weak links dominating in low-quality films, detection caused by nonlinear magnetic flux motion. (orig.).

  10. Pentacene based thin film transistors with high-k dielectric Nd2O3 as a gate insulator

    International Nuclear Information System (INIS)

    Sarma, R.; Saikia, D.

    2010-01-01

    We have investigated the pentacene based Organic Thin Film Transistors (OTFTs) with high-k dielectric Nd 2 O 3 . Use of high dielectric constant (high-k) gate insulator Nd 2 O 3 reduces the threshold voltage and sub threshold swing of the OTFTs. The calculated threshold voltage -2.2V and sub-threshold swing 1V/decade, current ON-OFF ratio is 1.7 X 10 4 and mobility is 0.13cm 2 /V.s. Pentacene film is deposited on Nd 2 O 3 surface using two step deposition method. Deposited pentacene film is found poly crystalline in nature. (author)

  11. Visual search behaviours and verbal reports during film-based and in situ representative tasks in volleyball.

    Science.gov (United States)

    Afonso, José; Garganta, Júlio; McRobert, Allistair; Williams, Mark; Mesquita, Isabel

    2014-01-01

    Several researchers have explored the processes underlying perceptual-cognitive expertise, mainly using film-based studies. However, few have compared the extent to which data from film-based settings differ from those obtained through in situ collection. This gap in the literature is a relevant concern, since scientific research is used to provide guidance for designing training programmes. In this paper, eye movement recording and verbal reports of thinking were combined to explore the processes underpinning skilled performance in a representative volleyball task involving both film-based and in situ data collection. Nine volleyball players performed as backcourt defenders while wearing an eye-tracking device and providing verbal reports of thinking after each sequence. A number of significant differences were observed between the data gathered under film-based and in situ conditions. Namely, in the in situ condition participants employed longer fixations (728.11 ± 129.27 ms) than in the film condition (659.57 ± 178.06 ms), and there were differences in the nature of the fixation locations. With respect to verbal reports, participants exhibited superior level of sophistication in the in situ condition (2.57 ± 0.50 vs. 2.30 ± 0.84 in the film condition), while denoting a greater concern with the opponents under this condition (1.00 ± 0.73) than in the film condition (0.59 ± 0.60). These differences emerged despite task design and constraints being highly similar. No differences were apparent in the number of gaze fixations and fixation locations across conditions or in the number of verbalised condition concepts. Although exploratory, our data suggest that the mechanisms underpinning skilled decision-making in sports differ between film-based and in situ conditions.

  12. High-Performance Complementary Transistors and Medium-Scale Integrated Circuits Based on Carbon Nanotube Thin Films.

    Science.gov (United States)

    Yang, Yingjun; Ding, Li; Han, Jie; Zhang, Zhiyong; Peng, Lian-Mao

    2017-04-25

    Solution-derived carbon nanotube (CNT) network films with high semiconducting purity are suitable materials for the wafer-scale fabrication of field-effect transistors (FETs) and integrated circuits (ICs). However, it is challenging to realize high-performance complementary metal-oxide semiconductor (CMOS) FETs with high yield and stability on such CNT network films, and this difficulty hinders the development of CNT-film-based ICs. In this work, we developed a doping-free process for the fabrication of CMOS FETs based on solution-processed CNT network films, in which the polarity of the FETs was controlled using Sc or Pd as the source/drain contacts to selectively inject carriers into the channels. The fabricated top-gated CMOS FETs showed high symmetry between the characteristics of n- and p-type devices and exhibited high-performance uniformity and excellent scalability down to a gate length of 1 μm. Many common types of CMOS ICs, including typical logic gates, sequential circuits, and arithmetic units, were constructed based on CNT films, and the fabricated ICs exhibited rail-to-rail outputs because of the high noise margin of CMOS circuits. In particular, 4-bit full adders consisting of 132 CMOS FETs were realized with 100% yield, thereby demonstrating that this CMOS technology shows the potential to advance the development of medium-scale CNT-network-film-based ICs.

  13. A volatile-solvent gas fiber sensor based on polyaniline film coated on superstructure fiber Bragg gratings

    International Nuclear Information System (INIS)

    Ai, L; Chen, T C; Su, W K; Mau, J C; Liu, W F

    2008-01-01

    A fiber sensor based on a polyaniline (PANI) film that is coated on the surface of an etched superstructure fiber grating to detect volatile solvent vapors is experimentally demonstrated. This sensing mechanism is based on the interaction of the testing gas with the polyaniline coating film, which changes the film index, resulting in a shift in the Bragg wavelength. The sensitivity of this sensor to ammonia (NH 3 ) gas is about 0.073 pm ppm −1 , which depends on the optical characteristics of the fiber grating, the diameter of the fiber cladding and the constituents of the sensing film. Methanol concentrations can also be measured using this sensing scheme. The sensitivity of this sensor must be improved to provide a simple, reliable, repeatable and non-destructive method for sensing various chemical gases. (technical design note)

  14. Data of thermal degradation and dynamic mechanical properties of starch-glycerol based films with citric acid as crosslinking agent.

    Science.gov (United States)

    González Seligra, Paula; Medina Jaramillo, Carolina; Famá, Lucía; Goyanes, Silvia

    2016-06-01

    Interest in biodegradable edible films as packaging or coating has increased because their beneficial effects on foods. In particular, food products are highly dependents on thermal stability, integrity and transition process temperatures of the packaging. The present work describes a complete data of the thermal degradation and dynamic mechanical properties of starch-glycerol based films with citric acid (CA) as crosslinking agent described in the article titled: "Biodegradable and non-retrogradable eco-films based on starch-glycerol with citric acid as crosslinking agent" González Seligra et al. (2016) [1]. Data describes thermogravimetric and dynamical mechanical experiences and provides the figures of weight loss and loss tangent of the films as a function of the temperature.

  15. Fully transparent thin-film transistor devices based on SnO2 nanowires.

    Science.gov (United States)

    Dattoli, Eric N; Wan, Qing; Guo, Wei; Chen, Yanbin; Pan, Xiaoqing; Lu, Wei

    2007-08-01

    We report on studies of field-effect transistor (FET) and transparent thin-film transistor (TFT) devices based on lightly Ta-doped SnO2 nano-wires. The nanowire-based devices exhibit uniform characteristics with average field-effect mobilities exceeding 100 cm2/V x s. Prototype nano-wire-based TFT (NW-TFT) devices on glass substrates showed excellent optical transparency and transistor performance in terms of transconductance, bias voltage range, and on/off ratio. High on-currents and field-effect mobilities were obtained from the NW-TFT devices even at low nanowire coverage. The SnO2 nanowire-based TFT approach offers a number of desirable properties such as low growth cost, high electron mobility, and optical transparency and low operation voltage, and may lead to large-scale applications of transparent electronics on diverse substrates.

  16. Nanopatterned yttrium aluminum garnet phosphor incorporated film for high-brightness GaN-based white light emitting diodes

    International Nuclear Information System (INIS)

    Cho, Joong-yeon; Park, Sang-Jun; Ahn, Jinho; Lee, Heon

    2014-01-01

    In this study, we fabricated high-brightness white light emitting diodes (LEDs) by developing a nanopatterned yttrium aluminum garnet (YAG) phosphor-incorporated film. White light can be obtained by mixing blue light from a GaN-based LED and yellow light of the YAG phosphor-incorporated film. If white light sources can be fabricated by exciting proper yellow phosphor using blue light, then these sources can be used instead of the conventional fluorescent lamps with a UV source, for backlighting of displays. In this work, a moth-eye structure was formed on the YAG phosphor-incorporated film by direct spin-on glass (SOG) printing. The moth-eye structures have been investigated to improve light transmittance in various optoelectronic devices, including photovoltaic solar cells, light emitting diodes, and displays, because of their anti-reflection property. Direct SOG printing, which is a simple, easy, and relatively inexpensive process, can be used to fabricate nanoscale structures. After direct SOG printing, the moth-eye structure with a diameter of 220 nm was formed uniformly on the YAG phosphor-incorporated film. As a result of moth-eye patterning on the YAG phosphor-incorporated film, the light output power of a white LED with a patterned YAG phosphor-incorporated film increased to up to 13% higher than that of a white LED with a non-patterned film. - Highlights: • GaN-based high-brightness white LED was prepared using patterned YAG phosphor-incorporated films. • Direct hydrogen silsesquioxane printing was used to form moth-eye patterns on the YAG films. • The electroluminescence intensity of the white LED was enhanced by up to 14.9%

  17. Nanopatterned yttrium aluminum garnet phosphor incorporated film for high-brightness GaN-based white light emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Joong-yeon; Park, Sang-Jun [Department of Materials Science and Engineering, Korea University, Seoul 136-713 (Korea, Republic of); Ahn, Jinho, E-mail: jhahn@hanyang.ac.kr [Department of Material Science and Engineering, Hanyang University, Seoul 133-791 (Korea, Republic of); Lee, Heon, E-mail: heonlee@korea.ac.kr [Department of Materials Science and Engineering, Korea University, Seoul 136-713 (Korea, Republic of)

    2014-11-03

    In this study, we fabricated high-brightness white light emitting diodes (LEDs) by developing a nanopatterned yttrium aluminum garnet (YAG) phosphor-incorporated film. White light can be obtained by mixing blue light from a GaN-based LED and yellow light of the YAG phosphor-incorporated film. If white light sources can be fabricated by exciting proper yellow phosphor using blue light, then these sources can be used instead of the conventional fluorescent lamps with a UV source, for backlighting of displays. In this work, a moth-eye structure was formed on the YAG phosphor-incorporated film by direct spin-on glass (SOG) printing. The moth-eye structures have been investigated to improve light transmittance in various optoelectronic devices, including photovoltaic solar cells, light emitting diodes, and displays, because of their anti-reflection property. Direct SOG printing, which is a simple, easy, and relatively inexpensive process, can be used to fabricate nanoscale structures. After direct SOG printing, the moth-eye structure with a diameter of 220 nm was formed uniformly on the YAG phosphor-incorporated film. As a result of moth-eye patterning on the YAG phosphor-incorporated film, the light output power of a white LED with a patterned YAG phosphor-incorporated film increased to up to 13% higher than that of a white LED with a non-patterned film. - Highlights: • GaN-based high-brightness white LED was prepared using patterned YAG phosphor-incorporated films. • Direct hydrogen silsesquioxane printing was used to form moth-eye patterns on the YAG films. • The electroluminescence intensity of the white LED was enhanced by up to 14.9%.

  18. Effect of gamma radiation on the mechanical and barrier properties of HEMA grafted chitosan-based films

    International Nuclear Information System (INIS)

    Khan, Avik; Huq, Tanzina; Khan, Ruhul A.; Dussault, Dominic; Salmieri, Stephane; Lacroix, Monique

    2012-01-01

    Chitosan films were prepared by dissolving 1% (w/v) chitosan powder in 2% (w/v) aqueous acetic acid solution. Chitosan films were prepared by solution casting. The values of puncture strength (PS), viscoelasticity coefficient and water vapor permeability (WVP) of the films were found to be 565 N/mm, 35%, and 3.30 g mm/m 2 day kPa, respectively. Chitosan solution was exposed to gamma irradiation (0.1–5 kGy) and it was revealed that PS values were reduced significantly (p≤0.05) after 1 kGy dose and it was not possible to form films after 5 kGy. Monomer, 2-hydroxyethyl methacrylate (HEMA) solution (0.1–1%, w/v) was incorporated into the chitosan solution and the formulation was exposed to gamma irradiation (0.3 kGy). A 0.1% (w/v) HEMA concentration at 0.3 kGy dose was found optimal-based on PS values for chitosan grafting. Then radiation dose (0.1–5 kGy) was optimized for HEMA grafting. The highest PS values (672 N/mm) were found at 0.7 kGy. The WVP of the grafted films improved significantly (p≤0.05) with the rise of radiation dose. - highlights: ► HEMA and Silane monomer were incorporated into the MC-based formulation and films. ► Films were exposed to gamma radiation. ► HEMA containing films showed the highest PS values. ► Surface morphology of the grafted films suggested better appearance.

  19. Plasma monitoring and PECVD process control in thin film silicon-based solar cell manufacturing

    Directory of Open Access Journals (Sweden)

    Gabriel Onno

    2014-02-01

    Full Text Available A key process in thin film silicon-based solar cell manufacturing is plasma enhanced chemical vapor deposition (PECVD of the active layers. The deposition process can be monitored in situ by plasma diagnostics. Three types of complementary diagnostics, namely optical emission spectroscopy, mass spectrometry and non-linear extended electron dynamics are applied to an industrial-type PECVD reactor. We investigated the influence of substrate and chamber wall temperature and chamber history on the PECVD process. The impact of chamber wall conditioning on the solar cell performance is demonstrated.

  20. Highly efficient electrochemical hydrogen evolution based on nickel diselenide nanowall film

    Science.gov (United States)

    Tang, Chun; Xie, Lisi; Sun, Xuping; Asiri, Abdullah M.; He, Yuquan

    2016-05-01

    In this letter, we report on hydrothermal growth of nickel diselenide nanowall film on carbon cloth (NiSe2 NW/CC) through topotactic transformation from a Ni(OH)2 precursor based on anion exchange reactions. When tested as an integrated 3D hydrogen-evolving cathode in strongly acidic media, NiSe2 NW/CC exhibits outstanding catalytic activity superior to its powder counterpart and strong long-term durability. It displays 10 and 100 mA cm-2 at overpotentials of 145 and 183 mV, respectively, with its catalytic activity being retained for 40 h.

  1. Plasmonic characterization of photo-induced silver nanoparticles extracted from silver halide based TEM film

    Energy Technology Data Exchange (ETDEWEB)

    Sudheer,, E-mail: sudheer@rrcat.gov.in; Tiwari, P.; Rai, V. N.; Srivastava, A. K. [Indus Synchrotrons Utilization Division, Raja Ramanna Centre for Advanced Technology Indore, Madhya Pradesh 452013 (India); Varshney, G. K. [Laser Bio-medical Applications & Instrumentation Division, Raja Ramanna Centre for Advanced Technology Indore, Madhya Pradesh 452013 (India)

    2016-05-23

    The plasmonic responses of silver nanoparticles extracted from silver halide based electron microscope film are investigated. Photo-reduction process is carried out to convert the silver halide grains into the metallic silver. The centrifuge technique is used for separating the silver nanoparticles from the residual solution. Morphological study performed by field emission scanning electron microscope (FESEM) shows that all the nanoparticles have an average diameter of ~120 nm with a high degree of mono dispersion in size. The localized surface plasmon resonance (LSPR) absorption peak at ~537 nm confirms the presence of large size silver nanoparticles.

  2. Variable-energy positron annihilation study of subnanopores in SiOCH-based PECVD films

    International Nuclear Information System (INIS)

    Ito, Kenji; Oka, Toshitaka; Kobayashi, Yoshinori; Suzuki, Ryoichi; Ohdaira, Toshiyuki

    2007-01-01

    Subnanoporosity was introduced into SiOCH-based thin films by mixing tetraethyl orthosilicate with hexamethyldisiloxane (HMDSO) in the plasma enhanced chemical vapor deposition process, and was evaluated by the variable-energy positron annihilation lifetime technique. It was found that with increasing the HMDSO fraction both porosity and pore size were enhanced, as evidenced by the decreased refractive index and increased ortho-positronium lifetime. The lifetimes from 2.0 to 6.8 ns suggested the tunable pore volumes within a range of 0.1-0.7 nm 3

  3. [Synthesis and Characterization of a Sugar Based Electrolyte for Thin-film Polymer Batteries

    Science.gov (United States)

    1998-01-01

    The work performed during the current renewal period, March 1,1998 focused primarily on the synthesis and characterization of a sugar based electrolyte for thin-film polymer batteries. The initial phase of the project involved developing a suitable sugar to use as the monomer in the polymeric electrolyte synthesis. The monomer has been synthesized and characterized completely. Overall the yield of this material is high and it can be produced in relatively large quantity easily and in high purity. The scheme used for the preparation of the monomer is outlined along with pertinent yields.

  4. Ambipolar organic thin-film transistor-based nano-floating-gate nonvolatile memory

    International Nuclear Information System (INIS)

    Han, Jinhua; Wang, Wei; Ying, Jun; Xie, Wenfa

    2014-01-01

    An ambipolar organic thin-film transistor-based nano-floating-gate nonvolatile memory was demonstrated, with discrete distributed gold nanoparticles, tetratetracontane (TTC), pentacene as the floating-gate layer, tunneling layer, and active layer, respectively. The electron traps at the TTC/pentacene interface were significantly suppressed, which resulted in an ambipolar operation in present memory. As both electrons and holes were supplied in the channel and trapped in the floating-gate by programming/erasing operations, respectively, i.e., one type of charge carriers was used to overwrite the other, trapped, one, a large memory window, extending on both sides of the initial threshold voltage, was realized

  5. Ambipolar organic thin-film transistor-based nano-floating-gate nonvolatile memory

    Energy Technology Data Exchange (ETDEWEB)

    Han, Jinhua; Wang, Wei, E-mail: wwei99@jlu.edu.cn; Ying, Jun; Xie, Wenfa [State Key Laboratory on Integrated Optoelectronics, College of Electronic Science and Engineering, Jilin University, 2699 Qianjin Street, Changchun 130012 (China)

    2014-01-06

    An ambipolar organic thin-film transistor-based nano-floating-gate nonvolatile memory was demonstrated, with discrete distributed gold nanoparticles, tetratetracontane (TTC), pentacene as the floating-gate layer, tunneling layer, and active layer, respectively. The electron traps at the TTC/pentacene interface were significantly suppressed, which resulted in an ambipolar operation in present memory. As both electrons and holes were supplied in the channel and trapped in the floating-gate by programming/erasing operations, respectively, i.e., one type of charge carriers was used to overwrite the other, trapped, one, a large memory window, extending on both sides of the initial threshold voltage, was realized.

  6. Unit cell determination of epitaxial thin films based on reciprocal space vectors by high-resolution X-ray diffractometry

    OpenAIRE

    Yang, Ping; Liu, Huajun; Chen, Zuhuang; Chen, Lang; Wang, John

    2013-01-01

    A new approach, based on reciprocal space vectors (RSVs), is developed to determine Bravais lattice types and accurate lattice parameters of epitaxial thin films by high-resolution X-ray diffractometry (HR-XRD). The lattice parameters of single crystal substrates are employed as references to correct the systematic experimental errors of RSVs of thin films. The general procedure is summarized, involving correction of RSVs, derivation of raw unit cell, subsequent conversion to the Niggli unit ...

  7. Study of thermal and mechanical properties of PCL films; Estudo das propriedades termicas de filmes a base de PCL

    Energy Technology Data Exchange (ETDEWEB)

    Siqueira, A.R. de; Vieira, A.B. da Silva; Leite, I.F., E-mail: itamaraf@gmail.com [Universidade Federal da Paraiba (UFPB), Joaoo Pessoa, PB (Brazil). Departamento de Engenharia de Materiais

    2016-07-01

    In the current situation of the market, it is remarkable the concern for the development of materials that offer better properties and biodegradable behavior. The scientific researches seeks development and improvement of materials for applications in products increasingly biodegradable. To do so, this research aims at obtaining films composed of polymer poly(ε-caprolactone)(PCL), aliphatic polyester synthetic and biodegradable, and silicates in layers, specifically in the State of Paraiba, prepared by the method of solution. This mixture makes it possible to form different nanostructures intercalated morphology and/or exfoliated, which therefore provides improvement in the thermal properties of the final product. After analyzing the results of X-ray diffraction (XRD) was observed predominantly exfoliated morphologies to PCL films containing different silicate content and an increase in thermal stability when there was a lower concentration of clay as thermal analysis (TGA). (author)

  8. Organic Thin Films Deposited by Emulsion-Based, Resonant Infrared, Matrix-Assisted Pulsed Laser Evaporation: Fundamentals and Applications

    Science.gov (United States)

    Ge, Wangyao

    Thin film deposition techniques are indispensable to the development of modern technologies as thin film based optical coatings, optoelectronic devices, sensors, and biological implants are the building blocks of many complicated technologies, and their performance heavily depends on the applied deposition technique. Particularly, the emergence of novel solution-processed materials, such as soft organic molecules, inorganic compounds and colloidal nanoparticles, facilitates the development of flexible and printed electronics that are inexpensive, light weight, green and smart, and these thin film devices represent future trends for new technologies. One appealing feature of solution-processed materials is that they can be deposited into thin films using solution-processed deposition techniques that are straightforward, inexpensive, high throughput and advantageous to industrialize thin film based devices. However, solution-processed techniques rely on wet deposition, which has limitations in certain applications, such as multi-layered film deposition of similar materials and blended film deposition of dissimilar materials. These limitations cannot be addressed by traditional, vacuum-based deposition techniques because these dry approaches are often too energetic and can degrade soft materials, such as polymers, such that the performance of resulting thin film based devices is compromised. The work presented in this dissertation explores a novel thin film deposition technique, namely emulsion-based, resonant infrared, matrix-assisted pulsed laser evaporation (RIR-MAPLE), which combines characteristics of wet and dry deposition techniques for solution-processed materials. Previous studies have demonstrated the feasibility of emulsion-based RIR-MAPLE to deposit uniform and continuous organic, nanoparticle and blended films, as well as hetero-structures that otherwise are difficult to achieve. However, fundamental understanding of the growth mechanisms that govern

  9. Thin-film encapsulation of organic electronic devices based on vacuum evaporated lithium fluoride as protective buffer layer

    Science.gov (United States)

    Peng, Yingquan; Ding, Sihan; Wen, Zhanwei; Xu, Sunan; Lv, Wenli; Xu, Ziqiang; Yang, Yuhuan; Wang, Ying; Wei, Yi; Tang, Ying

    2017-03-01

    Encapsulation is indispensable for organic thin-film electronic devices to ensure reliable operation and long-term stability. For thin-film encapsulating organic electronic devices, insulating polymers and inorganic metal oxides thin films are widely used. However, spin-coating of insulating polymers directly on organic electronic devices may destroy or introduce unwanted impurities in the underlying organic active layers. And also, sputtering of inorganic metal oxides may damage the underlying organic semiconductors. Here, we demonstrated that by utilizing vacuum evaporated lithium fluoride (LiF) as protective buffer layer, spin-coated insulating polymer polyvinyl alcohol (PVA), and sputtered inorganic material Er2O3, can be successfully applied for thin film encapsulation of copper phthalocyanine (CuPc)-based organic diodes. By encapsulating with LiF/PVA/LiF trilayer and LiF/Er2O3 bilayer films, the device lifetime improvements of 10 and 15 times can be achieved. These methods should be applicable for thin-film encapsulation of all kinds of organic electronic devices. Moisture-induced hole trapping, and Al top electrode oxidation are suggest to be the origins of current decay for the LiF/PVA/LiF trilayer and LiF/Er2O3 bilayer films encapsulated devices, respectively.

  10. Amorphous and crystalline In{sub 2}O{sub 3}-based transparent conducting films for photovoltaics

    Energy Technology Data Exchange (ETDEWEB)

    Koida, Takashi [Research Center for Photovoltaics, National Institute of Advanced Industrial Science and Technology, Tsukuba (Japan)

    2017-02-15

    We reported solar cells with reduced electrical and optical losses using hydrogen-doped In{sub 2}O{sub 3} (In{sub 2}O{sub 3}:H) transparent conducting layers with low sheet resistance and high transparence characteristics. The transparent conducting oxide (TCO) films were prepared by solid-phase crystallization of amorphous (a-) In{sub 2}O{sub 3}:H films grown by magnetron sputtering. The polycrystalline (poly-) In{sub 2}O{sub 3}:H films exhibited electron mobilities (over 100 cm{sup 2}V{sup -1} s{sup -1}) 2 and 3 times greater than those of conventional TCO films. This paper describes (i) the current status of the electrical properties of In{sub 2}O{sub 3}-based TCO; (ii) the structural and optoelectrical properties of the a-In{sub 2}O{sub 3}:H and poly-In{sub 2}O{sub 3}:H films, focusing on the inhomogeneity and stability characteristics of the films; and (iii) the electrical properties of bilayer TCO. The potential of these high mobility TCO films for solar cells was also described. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  11. Ultra-tough and strong, hybrid thin films based on ionically crosslinked polymers and 2D inorganic platelets

    Science.gov (United States)

    Ji, Dong Hwan; Choi, Suji; Kim, Jaeyun; nanobiomaterials lab Team

    Integration of high strength and toughness tend to be mutually exclusive and synthesized hybrid films with superior mechanical properties have been difficult to fabricate controllable shapes and various scales. Although diverse synthesized hybrid films consisting of organic matrix and inorganic materials with brick-and-mortar structure, show improved mechanical properties, these films are still limited in toughness and fabrication methods. Herein, we report ultra-tough and strong hybrid thin films with self-assembled uniform microstructures with controllable shapes and various scale based on hydrogel-mediated process. Ca2+-crosslinking in alginate chains and well-aligned alumina platelets in alginate matrix lead to a synergistic enhancement of strength and toughness in the resulting film. Consequentially, Ca2+-crosslinked Alg/Alu films showed outstanding toughness of 29 MJ m-3 and tensile strength of 160 MPa. Furthermore, modifying Alu surface with polyvinylpyrrolidone (PVP), tensile strength was further improved up to 200 MPa. Our results suggest an alternative approach to design and processing of self-assembled hydrogel-mediated hybrid films with outstanding mechanical properties.

  12. Photochromic and electrochromic performances of new types of donor/acceptor systems based on crosslinked polyviologen film and electron donors

    International Nuclear Information System (INIS)

    Gao Liping; Ding Guojing; Li Chaolong; Wang Yuechuan

    2011-01-01

    Viologen-functionalized copolymer COPV 2+ was synthesized by copolymer graft-modified, which was crosslinked by NH 3 .H 2 O gas-fumigated at 25 deg. C for 4 h due to the condensation of the siloxanes of COPV 2+ film. Simultaneously, different donor/acceptor systems had been prepared based on crosslinked polyviologen film (COPV 2+ ) and N,N,N',N'-tetramethyl-1,4-phenylenediamine (TMPD) or hydroxyethylferrocene (HEFc) in order to shorten the response times and improve contrast ratios in response to external photo- and potential stimuli. The evolution of structures from COPO to COPV 2+ is carefully characterized. The COPV 2+ /TMPD and COPV 2+ /HEFc films exhibited both photochromic and electrochromic performances. After UV irradiations, COPV 2+ /TMPD and COPV 2+ /HEFc films changed their colors from colorless to deep blue, while optical transmissions at 610 nm decreased about 64% and 75%, respectively. When removing out from UV irradiation, the colored COPV 2+ /TMPD and COPV 2+ /HEFc films faded to the original colors within about 60 min. When COPV 2+ /TMPD and COPV 2+ /HEFc films were biased with negative voltage of -2.5 V, they changed their colors from colorless to deep blue in 4 s and 3 s, while the optical transmissions at 556 nm decreased about 81% and 75%, respectively. When electric impulse was switched off, the colored COPV 2+ /TMPD and COPV 2+ /HEFc films faded to the original colors within about 7 s and 6 s, respectively.

  13. Measurement of surface charges on the dielectric film based on field mills under the HVDC corona wire

    Science.gov (United States)

    Donglai, WANG; Tiebing, LU; Yuan, WANG; Bo, CHEN; Xuebao, LI

    2018-05-01

    The ion flow field on the ground is one of the significant parameters used to evaluate the electromagnetic environment of high voltage direct current (HVDC) power lines. HVDC lines may cross the greenhouses due to the restricted transmission corridors. Under the condition of ion flow field, the dielectric films on the greenhouses will be charged, and the electric fields in the greenhouses may exceed the limit value. Field mills are widely used to measure the ground-level direct current electric fields under the HVDC power lines. In this paper, the charge inversion method is applied to calculate the surface charges on the dielectric film according to the measured ground-level electric fields. The advantages of hiding the field mill probes in the ground are studied. The charge inversion algorithm is optimized in order to decrease the impact of measurement errors. Based on the experimental results, the surface charge distribution on a piece of quadrate dielectric film under a HVDC corona wire is studied. The enhanced effect of dielectric film on ground-level electric field is obviously weakened with the increase of film height. Compared with the total electric field strengths, the normal components of film-free electric fields at the corresponding film-placed positions have a higher effect on surface charge accumulation.

  14. Efeito da adição de ácidos graxos em filmes à base de pectina The effect of addition of fatty acids on pectin films

    Directory of Open Access Journals (Sweden)

    Juliana A. Batista

    2005-12-01

    Full Text Available Os objetivos deste trabalho foram desenvolver filmes à base de pectina de baixo teor de esterificação, amidada, com adição dos ácidos graxos láurico (AL, palmítico (AP e esteárico (AE e caracterizá-los quanto às propriedades de permeabilidade ao vapor de água (PVA e ao oxigênio, propriedades mecânicas (tensão de ruptura e elongação, solubilidade em água e opacidade, além de observar a morfologia da superfície dos filmes utilizando microscopia eletrônica de varredura (MEV. A adição de 12 e 18% dos ácidos promoveu aumento da PVA e da elongação e redução da tensão de ruptura, em relação aos filmes com 6% de ácido graxo. Todos os filmes apresentaram-se 100% solúveis em água e mais opacos quando os ácidos graxos foram adicionados. A partir da MEV, foi observado que os ácidos graxos não se incorporaram à matriz filmogênica.The purposes of this research were to develop and characterize composite biofilms produced with low methoxyl amidated pectin plus lauric, palmitic and stearic acids. Water vapor permeability, oxigen permeability, mechanical properties (tensile strength and elongation, water solubility, opacity and, surface morphology were evaluated. The increase of fatty acids addition to 12 and 18% resulted in an increase in water vapor permeability and elongation and a decrease in tensile strength compared to the level of 6% of fatty acids. All formulations produced films showing 100% water solubility. As observed by scanning electronic microscopy the fatty acids were not homogeneously incorporated on the filmogenic matrices.

  15. Furfural Determination with Disposable Polymer Films and Smartphone-Based Colorimetry for Beer Freshness Assessment.

    Science.gov (United States)

    Rico-Yuste, Alberto; González-Vallejo, Victoria; Benito-Peña, Elena; de Las Casas Engel, Tomás; Orellana, Guillermo; Moreno-Bondi, María Cruz

    2016-04-05

    We have developed disposable color-changing polymeric films for quantification of furfural-a freshness indicator-in beer using a smartphone-based reader. The films are prepared by radical polymerization of 4-vinylaniline, as a furfural-sensitive indicator monomer, 2-hydroxymethyl methacrylate as a comonomer, and ethylene dimethyl methacrylate (EDMA) as a cross-linker. The sensing mechanism is based on the Stenhouse reaction in which aniline and furfural react in acidic media with the generation of a deep red cyanine derivative, absorbing at 537 nm, which is visible to the naked eye. The colorimetric response has been monitored using either a portable fiber-optic spectrophotometer or the built-in camera of a smartphone. Under the optimized conditions, a linear response to furfural in beer was obtained in the 39 to 500 μg L(-1) range, with a detection limit of 12 μg L(-1), thus improving the performance of other well-established colorimetric or chromatographic methods. The novel films are highly selective to furfural, and no cross-reactivity has been observed from other volatile compounds generated during beer aging. A smartphone application (app), developed for Android platforms, measures the RGB color coordinates of the sensing membranes after exposure to the analyte. Following data processing, the signals are converted into concentration values by preloaded calibration curves. The method has been applied to determination of furfural in pale lager beers with different storage times at room temperature. A linear correlation (r > 0.995) between the storage time and the furfural concentration in the samples has been confirmed; our results have been validated by HPLC with diode-array detection.

  16. Processing parameters for ZnO-based thick film varistors obtained by screen printing

    Directory of Open Access Journals (Sweden)

    de la Rubia, M. A.

    2006-06-01

    Full Text Available Thick film varistors based on the ZnO-Bi2O3-Sb2O3 system have been prepared by screen printing on dense alumina substrates. Different processing parameters like the paste viscosity, burn out and sintering cycles, green and sintered thickness, have been studied to improve the processing of ZnO-based thick film varistors. Starting powders were pre-treated in two different ways in order to control both the Bi-rich liquid phase formation and the excessive volatilization of Bi2O3 during sintering due to the high area/volume ratio of the thick films. Significant changes have been observed in the electrical properties related to the different firing schedule and selection of the starting powders.

    Se han preparado varistores basados en el sistema ZnO-Bi2O3-Sb2O3 en forma de lámina gruesa sobre sustratos de alúmina densa. Diferentes parámetros del procesamiento como la viscosidad de la pasta, los ciclos de calcinación y sinterización y el espesor en verde y sinterizado han sido estudiados para mejorar el procesamiento de los varistores basados en ZnO preparados en forma de lámina gruesa. Los polvos de partida fueron pretratados de dos formas diferentes con el objetivo de controlar la formación de la fase líquida rica en bismuto y la excesiva volatilización de Bi2O3 durante la sinterización debida a la alta relación área-volumen de las láminas gruesas. Se han observado cambios significativos en las propiedades eléctricas relacionadas con los diferentes ciclos de calcinado y con la selección de los polvos de partida.

  17. Note: Durability analysis of optical fiber hydrogen sensor based on Pd-Y alloy film.

    Science.gov (United States)

    Huang, Peng-cheng; Chen, You-ping; Zhang, Gang; Song, Han; Liu, Yi

    2016-02-01

    The Pd-Y alloy sensing film has an excellent property for hydrogen detection, but just for one month, the sensing film's property decreases seriously. To study the failure of the sensing film, the XPS spectra analysis was used to explore the chemical content of the Pd-Y alloy film, and analysis results demonstrate that the yttrium was oxidized. The paper presented that such an oxidized process was the potential reason of the failure of the sensing film. By understanding the reason of the failure of the sensing film better, we could improve the manufacturing process to enhance the property of hydrogen sensor.

  18. Structural study of TiO2-based transparent conducting films

    International Nuclear Information System (INIS)

    Hitosugi, T.; Yamada, N.; Nakao, S.; Hatabayashi, K.; Shimada, T.; Hasegawa, T.

    2008-01-01

    We have investigated microscopic structures of sputter and pulsed laser deposited (PLD) anatase Nb-doped TiO 2 transparent conducting films, and discuss what causes the degradation of resistivity in sputter-deposited films. Cross-sectional transmission electron microscope and polarized optical microscope images show inhomogeneous intragrain structures and small grains of ∼10 μm in sputter-deposited films. From comparison with PLD films, these results suggest that homogeneous film growth is the important factor to obtain highly conducting sputter-deposited film

  19. Si-based thin film coating on Y-TZP: Influence of deposition parameters on adhesion of resin cement

    Energy Technology Data Exchange (ETDEWEB)

    Queiroz, José Renato Cavalcanti, E-mail: joserenatocq@hotmail.com [Potiguar University, Department of Biotechnology, Natal (Brazil); Nogueira Junior, Lafayette [São Paulo State University, Department of Prosthodontics and Dental Materials, São José dos Campos (Brazil); Massi, Marcos [Federal University of São Paulo, Institute of Science and Technology, São José dos Campos (Brazil); Silva, Alecssandro de Moura; Bottino, Marco Antonio [São Paulo State University, Department of Prosthodontics and Dental Materials, São José dos Campos (Brazil); Sobrinho, Argemiro Soares da Silva [Technological Institute of Aeronautics, Department of Physics, São José dos Campos (Brazil); Özcan, Mutlu [University of Zurich, Dental Materials Unit, Center for Dental and Oral Medicine, Clinic for Fixed and Removable Prosthodontics and Dental Materials Science, Zurich (Switzerland)

    2013-10-01

    This study evaluated the influence of deposition parameters for Si-based thin films using magnetron sputtering for coating zirconia and subsequent adhesion of resin cement. Zirconia ceramic blocks were randomly divided into 8 groups and specimens were either ground finished and polished or conditioned using air-abrasion with alumina particles coated with silica. In the remaining groups, the polished specimens were coated with Si-based film coating with argon/oxygen magnetron discharge at 8:1 or 20:1 flux. In one group, Si-based film coating was performed on air-abraded surfaces. After application of bonding agent, resin cement was bonded. Profilometry, goniometry, Energy Dispersive X-ray Spectroscopy and Rutherford Backscattering Spectroscopy analysis were performed on the conditioned zirconia surfaces. Adhesion of resin cement to zirconia was tested using shear bond test and debonded surfaces were examined using Scanning Electron Microscopy. Si-based film coating applied on air-abraded rough zirconia surfaces increased the adhesion of the resin cement (22.78 ± 5.2 MPa) compared to those of other methods (0–14.62 MPa) (p = 0.05). Mixed type of failures were more frequent in Si film coated groups on either polished or air-abraded groups. Si-based thin films increased wettability compared to the control group but did not change the roughness, considering the parameters evaluated. Deposition parameters of Si-based thin film and after application of air-abrasion influenced the initial adhesion of resin cement to zirconia.

  20. Si-based thin film coating on Y-TZP: Influence of deposition parameters on adhesion of resin cement

    International Nuclear Information System (INIS)

    Queiroz, José Renato Cavalcanti; Nogueira Junior, Lafayette; Massi, Marcos; Silva, Alecssandro de Moura; Bottino, Marco Antonio; Sobrinho, Argemiro Soares da Silva; Özcan, Mutlu

    2013-01-01

    This study evaluated the influence of deposition parameters for Si-based thin films using magnetron sputtering for coating zirconia and subsequent adhesion of resin cement. Zirconia ceramic blocks were randomly divided into 8 groups and specimens were either ground finished and polished or conditioned using air-abrasion with alumina particles coated with silica. In the remaining groups, the polished specimens were coated with Si-based film coating with argon/oxygen magnetron discharge at 8:1 or 20:1 flux. In one group, Si-based film coating was performed on air-abraded surfaces. After application of bonding agent, resin cement was bonded. Profilometry, goniometry, Energy Dispersive X-ray Spectroscopy and Rutherford Backscattering Spectroscopy analysis were performed on the conditioned zirconia surfaces. Adhesion of resin cement to zirconia was tested using shear bond test and debonded surfaces were examined using Scanning Electron Microscopy. Si-based film coating applied on air-abraded rough zirconia surfaces increased the adhesion of the resin cement (22.78 ± 5.2 MPa) compared to those of other methods (0–14.62 MPa) (p = 0.05). Mixed type of failures were more frequent in Si film coated groups on either polished or air-abraded groups. Si-based thin films increased wettability compared to the control group but did not change the roughness, considering the parameters evaluated. Deposition parameters of Si-based thin film and after application of air-abrasion influenced the initial adhesion of resin cement to zirconia.

  1. Effects of Hydrolysed Whey Proteins on the Techno-Functional Characteristics of Whey Protein-Based Films

    Directory of Open Access Journals (Sweden)

    Klaus Noller

    2013-03-01

    Full Text Available Pure whey protein isolate (WPI-based cast films are very brittle due to its strong formation of protein cross-linking of disulphide bonding, hydrogen bonding as well as hydrophobic and electrostatic interactions. However, this strong cross-linking is the reason for its final barrier performance. To overcome film brittleness of whey protein layers, plasticisers like glycerol are used. It reduces intermolecular interactions, increases the mobility of polymer chains and thus film flexibility can be achieved. The objective of this study was to investigate the influence of hydrolysed whey protein isolate (WPI in whey protein isolate-based cast films on their techno-functional properties. Due to the fact, that the addition of glycerol is necessary but at the same time increases the free volume in the film leading to higher oxygen and water vapour permeability, the glycerol concentration was kept constant. Cast films with different ratios of hydrolysed and not hydrolysed WPI were produced. They were characterised in order to determine the influence of the lower molecular weight caused by the addition of hydrolysed WPI on the techno-functional properties. This study showed that increasing hydrolysed WPI concentrations significantly change the mechanical properties while maintaining the oxygen and water vapour permeability. The tensile and elastic film properties decreased significantly by reducing the average molecular weight whereas the yellowish coloration and the surface tension considerably increased. This study provided new data which put researchers and material developers in a position to tailor the characteristics of whey protein based films according to their intended application and further processing.

  2. Filmes biodegradáveis à base de proteínas miofibrilares de pescado Biodegradable films based on myofibrillar proteins of fish

    Directory of Open Access Journals (Sweden)

    Elessandra da Rosa Zavareze

    2012-05-01

    Full Text Available O objetivo deste trabalho foi estudar as propriedades físicas, mecânicas e de barreira dos filmes produzidos a partir de diferentes concentrações de proteínas miofibrilares de pescado de baixo valor comercial. O pescado utilizado foi a corvina (Micropogonias furnieri, que foi eviscerada e filetada. As proteínas miofibrilares foram obtidas do músculo, em sucessivas lavagens com água destilada. Os filmes foram produzidos com 3, 4 e 5% de proteínas miofibrilares pelo método de casting. Os filmes foram analisados nos seguintes aspectos: espessura, solubilidade, opacidade, resistência à tração, elongação e permeabilidade ao vapor de água (PVA. O aumento da concentração de proteínas miofibrilares atribuiu aos filmes maior espessura, opacidade, resistência à tração e PVA; no entanto, conferiu menor elongação na ruptura dos mesmos.The objective of this work was to study the physical, mechanical and barrier properties of the films produced from different concentrations of myofibrillar proteins of fish. The fish used was croaker (Micropogonias furnieri, which was gutted and filleted. The myofibrillar proteins were obtained through the muscle with successive washes with distilled water. The films were made with 3, 4 and 5% of myofibrillar proteins by the method of casting. The films were analyzed by thickness, solubility, opacity, tensile strength, elongation and water vapor permeability (PVA. The increase of myofibrillar proteins concentration in the films increased thickness, opacity, tensile strength and water vapor permeability and reduced elongation at break of the film.

  3. Preparation and characterization of graphene-based vanadium oxide composite semiconducting films with horizontally aligned nanowire arrays

    International Nuclear Information System (INIS)

    Jung, Hye-Mi; Um, Sukkee

    2016-01-01

    Highly oriented crystalline hybrid thin films primarily consisting of Magnéli-phase VO 2 and conductive graphene nanoplatelets are fabricated by a sol–gel process via dipping pyrolysis. A combination of chemical, microstructural, and electrical analyses reveals that graphene oxide (GO)-templated vanadium oxide (VO x ) nanocomposite films exhibit a vertically stacked multi-lamellar nanostructure consisting of horizontally aligned vanadium oxide nanowire (VNW) arrays along the (hk0) set of planes on a GO template, with an average crystallite size of 41.4 Å and a crystallographic tensile strain of 0.83%. In addition, GO-derived VO x composite semiconducting films, which have an sp 3 /sp 2 bonding ratio of 0.862, display thermally induced electrical switching properties in the temperature range of − 20 °C to 140 °C, with a transition temperature of approximately 65 °C. We ascribe these results to the use of GO sheets, which serve as a morphological growth template as well as an electrochemically tunable platform for enhancing the charge-carrier mobility. Moreover, the experimental studies demonstrate that graphene-based Magnéli-phase VO x composite semiconducting films can be used in advanced thermo-sensitive smart sensing/switching applications because of their outstanding thermo-electrodynamic properties and high surface charge density induced by the planar-type VNWs. - Highlights: • VO x -graphene oxide composite (G/VO x ) films were fabricated by sol–gel process. • The G/VO x films mainly consisted of Magnéli-phase VO 2 and reduced graphene sheets. • The G/VO x films exhibited multi-lamellar textures with planar VO x nanowire arrays. • The G/VO x films showed the thermo-sensitive electrical switching properties. • Effects of GOs on the electrical characteristics of the G/VO x films were discussed.

  4. Structure and giant magnetoresistance of carbon-based amorphous films prepared by magnetron sputtering

    International Nuclear Information System (INIS)

    Ma, L.; He, M.F.; Liu, Z.W.; Zeng, D.C.; Gu, Z.F.; Cheng, G.

    2014-01-01

    Pure amorphous carbon (a-C) and Co-doped Co x C 1−x films were prepared on n-Si(100) substrates by dc magnetron sputtering. In Co–C films, the nano-sized amorphous Co particles were homogeneously dispersed in the amorphous cross-linked carbon matrix. The structures of a-C and Co x C 1−x films were investigated by X-ray photoelectron spectroscopy and Raman spectroscopy. The results showed that the a-C films were diamond-like carbon (DLC) films. After doping cobalt into DLC film, the sp 3 -hybridized carbon content in DLC composite films almost had no change. The as-deposited Co x C 1−x granular films had larger value of magnetoresistance (MR) than the amorphous carbon film. A very high positive MR, up to 15.5% at magnetic field B = 0.8 T and x = 2.5 at.% was observed in a Co x C 1−x granular film with thickness of 80 nm at room temperature when the external magnetic field was perpendicular to the electric current and the film surface. With increase of the film thickness and Co-doped content, the MR decreased gradually. It remains a challenge to well explain the observed MR effect in the Co x C 1−x granular films. - Highlights: • The amorphous carbon films were diamond-like carbon films. • No carbide appearing, the Co–C composite films form a good metal/insulator system. • A high positive magnetoresistance, up to 15.5% at B = 0.8 T was observed in Co–C films

  5. Morphological, mechanical, barrier and properties of films based on acetylated starch and cellulose from barley.

    Science.gov (United States)

    El Halal, Shanise Lisie Mello; Colussi, Rosana; Biduski, Bárbara; Evangelho, Jarine Amaral do; Bruni, Graziella Pinheiro; Antunes, Mariana Dias; Dias, Alvaro Renato Guerra; Zavareze, Elessandra da Rosa

    2017-01-01

    Biodegradable films of native or acetylated starches with different concentrations of cellulose fibers (0%, 10% and 20%) were prepared. The films were characterized by morphological, mechanical, barrier, and thermal properties. The tensile strength of the acetylated starch film was lower than those of the native starch film, without fibers. The addition of fibers increased the tensile strength and decreased the elongation and the moisture of native and acetylated starches films. The acetylated starch film showed higher water solubility when compared to native starch film. The addition of cellulose fibers reduced the water solubility of the acetylated starch film. The films reinforced with cellulose fiber exhibited a higher initial decomposition temperature and thermal stability. The mechanical, barrier, solubility, and thermal properties are factors which direct the type of the film application in packaging for food products. The films elaborated with acetylated starches of low degree of substitution were not effective in a reduction of the water vapor permeability. The addition of the cellulose fiber in acetylated and native starches films can contribute to the development of more resistant films to be applied in food systems that need to maintain their integrity. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  6. Electrical characterisation of ferroelectric field effect transistors based on ferroelectric HfO2 thin films

    International Nuclear Information System (INIS)

    Yurchuk, Ekaterina

    2015-01-01

    Ferroelectric field effect transistor (FeFET) memories based on a new type of ferroelectric material (silicon doped hafnium oxide) were studied within the scope of the present work. Utilisation of silicon doped hafnium oxide (Si:HfO 2 ) thin films instead of conventional perovskite ferroelectrics as a functional layer in FeFETs provides compatibility to the CMOS process as well as improved device scalability. The influence of different process parameters on the properties of Si:HfO 2 thin films was analysed in order to gain better insight into the occurrence of ferroelectricity in this system. A subsequent examination of the potential of this material as well as its possible limitations with the respect to the application in non-volatile memories followed. The Si:HfO 2 -based ferroelectric transistors that were fully integrated into the state-of-the-art high-k metal gate CMOS technology were studied in this work for the first time. The memory performance of these devices scaled down to 28 nm gate length was investigated. Special attention was paid to the charge trapping phenomenon shown to significantly affect the device behaviour.

  7. An Electrochemical Quartz Crystal Microbalance Multisensor System Based on Phthalocyanine Nanostructured Films: Discrimination of Musts

    Directory of Open Access Journals (Sweden)

    Celia Garcia-Hernandez

    2015-11-01

    Full Text Available An array of electrochemical quartz crystal electrodes (EQCM modified with nanostructured films based on phthalocyanines was developed and used to discriminate musts prepared from different varieties of grapes. Nanostructured films of iron, nickel and copper phthalocyanines were deposited on Pt/quartz crystals through the Layer by Layer technique by alternating layers of the corresponding phthalocyanine and poly-allylamine hydrochloride. Simultaneous electrochemical and mass measurements were used to study the mass changes accompanying the oxidation of electroactive species present in must samples obtained from six Spanish varieties of grapes (Juan García, Prieto Picudo, Mencía Regadío, Cabernet Sauvignon, Garnacha and Tempranillo. The mass and voltammetric outputs were processed using three-way models. Parallel Factor Analysis (PARAFAC was successfully used to discriminate the must samples according to their variety. Multi-way partial least squares (N-PLS evidenced the correlations existing between the voltammetric data and the polyphenolic content measured by chemical methods. Similarly, N-PLS showed a correlation between mass outputs and parameters related to the sugar content. These results demonstrated that electronic tongues based on arrays of EQCM sensors can offer advantages over arrays of mass or voltammetric sensors used separately.

  8. Fabrication and characterization of high-mobility solution-based chalcogenide thin-film transistors

    KAUST Repository

    Mejia, Israel I.; Salas Villaseñ or, Ana L.; Cha, Dong Kyu; Alshareef, Husam N.; Gnade, Bruce E.; Quevedo-Ló pez, Manuel Angel Quevedo

    2013-01-01

    We report device and material considerations for the fabrication of high-mobility thin-film transistors (TFTs) compatible with large-area and inexpensive processes. In particular, this paper reports photolithographically defined n-type TFTs (n-TFTs) based on cadmium sulfide (CdS) films deposited using solution-based techniques. The integration process consists of four mask levels with a maximum processing temperature of 100 °C. The TFT performance was analyzed in terms of the CdS semiconductor thickness and as a function of postdeposition annealing in a reducing ambient. The IonI off ratios are ∼107 with field-effect mobilities of ∼5.3 and ∼4.7cm2V̇s for Al and Au source-drain contacts, respectively, using 70 nm of CdS. Transmission electron microscopy and electron energy loss spectroscopy were used to analyze the CdS-metal interfaces. © 1963-2012 IEEE.

  9. Performance improvement induced by asymmetric Y2O3-coated device structure to carbon-nanotube-film based photodetectors

    Science.gov (United States)

    Wang, Fanglin; Xu, Haitao; Huang, Huixin; Ma, Ze; Wang, Sheng; Peng, Lian-Mao

    2017-11-01

    Film-based semiconducting carbon nanotube (CNT) photodetectors are promising candidates for industrial applications. However, unintentional doping from the environment such as water/oxygen (H2O/O2) redox, polymers, etc. changes the doping level of the CNT film. Here, we evaluate the performance of film-based barrier-free bipolar diodes (BFBDs), which are basically semiconducting CNT films asymmetrically contacted by perfect n-type ohmic contact (scandium, Sc) and p-type ohmic contact (palladium, Pd) at the two ends of the diode. We show that normal BFBD devices have large variances of forward current, reverse current, and photocurrent for different doping levels of the channel. We propose an asymmetric Y2O3-coated BFBD device in which the channel is covered by a layer of an Y2O3 film and an overlap between the Sc electrode and the Y2O3 film is designed. The Y2O3 film provides p-type doping to the channel. The overlap section increases the length of the base of the pn junction, and the diffusion current of holes is suppressed. In this way, the rectifier factors (current ratio when voltages are at +0.5 V and -0.5 V) of the asymmetric Y2O3-coated BFBD devices are around two orders of magnitude larger and the photocurrent generation is more stable compared to that of normal devices. Our results provide a way to conquer the influence of unintentional doping from the environment and suppress reverse current in pn diodes. This is beneficial to applications of CNT-based photodetectors and of importance for inspiring methods to improve the performances of devices based on other low dimensional materials.

  10. Effect of antimicrobial on mechanical, barrier and optical properties of corn starch based self-supporting edible film

    Directory of Open Access Journals (Sweden)

    Tanima Chowdhury

    2013-10-01

    Full Text Available Antimicrobials like potassium sorbate, sodium propionate, and benzoic acid were incorporated in corn starch based formulation to investigate their effect on mechanical, water vapour barrier and optical properties of the developed self supporting edible film. The film was prepared by casting technique. When incorporated at 1.40% and above, potassium sorbate decreased the tensile strength (about 22% and increased the elongation (about 55% of control film; whereas, it increased the water vapour permeability by 15% only when added at 2.66%. At 2.66%, benzoic acid reduced the tensile strength by 24% and sodium propionate increased elongation by 17%. These two antimicrobials did not change the water vapour permeability. However, all the three antimicrobials adversely affected the optical properties by decreasing the whiteness index, increasing yellowness index, and reducing the surface gloss, with potassium sorbate showing the maximum effect. Among the three antimicrobials, sodium propionate appeared to be the best with minimum deterioration of film properties.

  11. Growth of Highly Epitaxial YBa2Cu3O7-δ Films from a Simple Propionate-Based Solution

    DEFF Research Database (Denmark)

    Yue, Zhao; Torres, Pol; Tang, Xiao

    2015-01-01

    Intensive investigations have been conducted to develop epitaxial oxide thin films with superior electromagnetic performance by low-cost chemical solution deposition routes. In this paper, a novel propionate-based precursor solution without involving any other additive was proposed and employed...... to grow superconducting YBa2Cu3O7-δ (YBCO) films on LaAlO3 (LAO) single crystals. The precursor solutions are stable with a long shelf life of up to several months. Since the primary compositions are propionates after evaporating the solvent, the toxic reagents and evolved gases during solution synthesis...... and heat treatment can be eliminated completely. In this process, rapid pyrolysis and high conversation rate can also be achieved during growth of YBCO films in comparison with the conventional trifluoroacetate metal organic deposition routes. Remarkably, a 210 nm YBCO film exhibits high superconducting...

  12. Comparison of computed tomography scout based reference point localization to conventional film and axial computed tomography.

    Science.gov (United States)

    Jiang, Lan; Templeton, Alistair; Turian, Julius; Kirk, Michael; Zusag, Thomas; Chu, James C H

    2011-01-01

    Identification of source positions after implantation is an important step in brachytherapy planning. Reconstruction is traditionally performed from films taken by conventional simulators, but these are gradually being replaced in the clinic by computed tomography (CT) simulators. The present study explored the use of a scout image-based reconstruction algorithm that replaces the use of traditional film, while exhibiting low sensitivity to metal-induced artifacts that can appear in 3D CT methods. In addition, the accuracy of an in-house graphical software implementation of scout-based reconstruction was compared with seed location reconstructions for 2 phantoms by conventional simulator and CT measurements. One phantom was constructed using a planar fixed grid of 1.5-mm diameter ball bearings (BBs) with 40-mm spacing. The second was a Fletcher-Suit applicator embedded in Styrofoam (Dow Chemical Co., Midland, MI) with one 3.2-mm-diameter BB inserted into each of 6 surrounding holes. Conventional simulator, kilovoltage CT (kVCT), megavoltage CT, and scout-based methods were evaluated by their ability to calculate the distance between seeds (40 mm for the fixed grid, 30-120 mm in Fletcher-Suit). All methods were able to reconstruct the fixed grid distances with an average deviation of <1%. The worst single deviations (approximately 6%) were exhibited in the 2 volumetric CT methods. In the Fletcher-Suit phantom, the intermodality agreement was within approximately 3%, with the conventional sim measuring marginally larger distances, with kVCT the smallest. All of the established reconstruction methods exhibited similar abilities to detect the distances between BBs. The 3D CT-based methods, with lower axial resolution, showed more variation, particularly with the smaller BBs. With a software implementation, scout-based reconstruction is an appealing approach because it simplifies data acquisition over film-based reconstruction without requiring any specialized equipment

  13. Effect of Grain Boundaries on the Performance of Thin-Film-Based Polycrystalline Silicon Solar Cells: A Numerical Modeling

    Science.gov (United States)

    Chhetri, Nikita; Chatterjee, Somenath

    2018-01-01

    Solar cells/photovoltaic, a renewable energy source, is appraised to be the most effective alternative to the conventional electrical energy generator. A cost-effective alternative of crystalline wafer-based solar cell is thin-film polycrystalline-based solar cell. This paper reports the numerical analysis of dependency of the solar cell parameters (i.e., efficiency, fill factor, open-circuit voltage and short-circuit current density) on grain size for thin-film-based polycrystalline silicon (Si) solar cells. A minority carrier lifetime model is proposed to do a correlation between the grains, grain boundaries and lifetime for thin-film-based polycrystalline Si solar cells in MATLAB environment. As observed, the increment in the grain size diameter results in increase in minority carrier lifetime in polycrystalline Si thin film. A non-equivalent series resistance double-diode model is used to find the dark as well as light (AM1.5) current-voltage (I-V) characteristics for thin-film-based polycrystalline Si solar cells. To optimize the effectiveness of the proposed model, a successive approximation method is used and the corresponding fitting parameters are obtained. The model is validated with the experimentally obtained results reported elsewhere. The experimentally reported solar cell parameters can be found using the proposed model described here.

  14. Comparative study of experimental and numerical behaviors of microwave absorbers based on ultrathin Al and Cu films

    Energy Technology Data Exchange (ETDEWEB)

    Costa, D.S., E-mail: daniel_eng_aero@hotmail.com [Instituto de Ciência e Tecnologia/UNIFESP, Rua Talim, 330, CEP 12.231-280, São José dos Campos, SP (Brazil); Nohara, E.L. [Universidade de Taubaté, Rua Daniel Danelli, s/n, CEP 12060-440, Taubaté, SP (Brazil); Rezende, M.C. [Instituto de Ciência e Tecnologia/UNIFESP, Rua Talim, 330, CEP 12.231-280, São José dos Campos, SP (Brazil)

    2017-06-15

    The study of radar absorbing materials increasingly thin, lightweight and flexible has gained growing importance in recent years. In military area these characteristics allow the reduction of weight and volume of platforms, and in civilian sector these materials stimulate innovative projects of electronic and microwave devices. The present work was devoted to studying ultrathin films of Al (20–80 nm) and Cu (10–100 nm) deposited on poly(ethylene terephthalate) (PET) substrate by magnetron sputtering technique. The electrical conductivity values of the films were determined by 4 probes method, the S parameters (S{sub 11} and S{sub 12}) were obtained by transmission line using a X-band waveguide and the skin depth calculated. The results show the dependence of the electrical conductivity with the thickness for both films. The experimental values of microwave attenuation were compared with calculated values based on the equivalent electric circuit theory. This comparison shows a good adjustment and confirms the use of electrical conductivity measurements to predict the microwave absorption behavior of ultrathin films. - Highlights: • This article focuses on recent progresses in ultrathin films aiming microwave absorption. • Nanometric films of Al and Cu deposited on poly(ethylene terephthalate) substrate were produced. • Electrical conductivity (4-probes) and S-parameters (S{sub 11} and S{sub 12}) of nanofilms were measured. • Calculated microwave attenuations were obtained based on the equivalent electric circuit theory. • A good fit between experimental and predictions data of microwave absorption was observed.

  15. How do evaporating thin films evolve? Unravelling phase-separation mechanisms during solvent-based fabrication of polymer blends

    KAUST Repository

    Wodo, Olga

    2014-10-13

    © 2014 AIP Publishing LLC. Solvent-based fabrication is a flexible and affordable approach to manufacture polymer thin films. The properties of products made from such films can be tailored by the internal organization (morphology) of the films. However, a precise knowledge of morphology evolution leading to the final film structure remains elusive, thus limiting morphology control to a trial and error approach. In particular, understanding when and where phases are formed, and how they evolve would provide rational guidelines for more rigorous control. Here, we identify four modes of phase formation and subsequent propagation within the thinning film during solvent-based fabrication. We unravel the origin and propagation characteristics of each of these modes. Finally, we construct a mode diagram that maps processing conditions with individual modes. The idea introduced here enables choosing processing conditions to tailor film morphology characteristics and paves the ground for a deeper understanding of morphology control with the ultimate goal of precise, yet affordable, morphology manipulation for a large spectrum of applications.

  16. How do evaporating thin films evolve? Unravelling phase-separation mechanisms during solvent-based fabrication of polymer blends

    KAUST Repository

    Wodo, Olga; Ganapathysubramanian, Baskar

    2014-01-01

    © 2014 AIP Publishing LLC. Solvent-based fabrication is a flexible and affordable approach to manufacture polymer thin films. The properties of products made from such films can be tailored by the internal organization (morphology) of the films. However, a precise knowledge of morphology evolution leading to the final film structure remains elusive, thus limiting morphology control to a trial and error approach. In particular, understanding when and where phases are formed, and how they evolve would provide rational guidelines for more rigorous control. Here, we identify four modes of phase formation and subsequent propagation within the thinning film during solvent-based fabrication. We unravel the origin and propagation characteristics of each of these modes. Finally, we construct a mode diagram that maps processing conditions with individual modes. The idea introduced here enables choosing processing conditions to tailor film morphology characteristics and paves the ground for a deeper understanding of morphology control with the ultimate goal of precise, yet affordable, morphology manipulation for a large spectrum of applications.

  17. Compositional and physicochemical factors governing the viability of Lactobacillus rhamnosus GG embedded in starch-protein based edible films

    Science.gov (United States)

    Soukoulis, Christos; Singh, Poonam; Macnaughtan, William; Parmenter, Christopher; Fisk, Ian D.

    2016-01-01

    Probiotic incorporation in edible films and coatings has been shown recently to be an efficient strategy for the delivery of probiotics in foods. In the present work, the impact of the compositional, physicochemical and structural properties of binary starch-protein edible films on Lactobacillus rhamnosus GG viability and stability was evaluated. Native rice and corn starch, as well as bovine skin gelatine, sodium caseinate and soy protein concentrate were used for the fabrication of the probiotic edible films. Starch and protein type both impacted the structural, mechanical, optical and thermal properties of the films, and the process loss of L. rhamnosus GG during evaporation-dehydration was significantly lower in the presence of proteins (0.91–1.07 log CFU/g) compared to solely starch based systems (1.71 log CFU/g). A synergistic action between rice starch and proteins was detected when monitoring the viability of L. rhamnosus GG over four weeks at fridge and room temperature conditions. In particular, a 3- to 7-fold increase in the viability of L. rhamnosus GG was observed in the presence of proteins, with sodium caseinate – rice starch based films offering the most enhanced stability. The film's shelf-life (as calculated using the FAO/WHO (2011) basis of 6 log viable CFU/g) ranged between 27-96 and 15–24 days for systems stored at fridge or room temperature conditions respectively. PMID:26726280

  18. Comparative study of experimental and numerical behaviors of microwave absorbers based on ultrathin Al and Cu films

    International Nuclear Information System (INIS)

    Costa, D.S.; Nohara, E.L.; Rezende, M.C.

    2017-01-01

    The study of radar absorbing materials increasingly thin, lightweight and flexible has gained growing importance in recent years. In military area these characteristics allow the reduction of weight and volume of platforms, and in civilian sector these materials stimulate innovative projects of electronic and microwave devices. The present work was devoted to studying ultrathin films of Al (20–80 nm) and Cu (10–100 nm) deposited on poly(ethylene terephthalate) (PET) substrate by magnetron sputtering technique. The electrical conductivity values of the films were determined by 4 probes method, the S parameters (S_1_1 and S_1_2) were obtained by transmission line using a X-band waveguide and the skin depth calculated. The results show the dependence of the electrical conductivity with the thickness for both films. The experimental values of microwave attenuation were compared with calculated values based on the equivalent electric circuit theory. This comparison shows a good adjustment and confirms the use of electrical conductivity measurements to predict the microwave absorption behavior of ultrathin films. - Highlights: • This article focuses on recent progresses in ultrathin films aiming microwave absorption. • Nanometric films of Al and Cu deposited on poly(ethylene terephthalate) substrate were produced. • Electrical conductivity (4-probes) and S-parameters (S_1_1 and S_1_2) of nanofilms were measured. • Calculated microwave attenuations were obtained based on the equivalent electric circuit theory. • A good fit between experimental and predictions data of microwave absorption was observed.

  19. Electrochromics for smart windows: Oxide-based thin films and devices

    International Nuclear Information System (INIS)

    Granqvist, Claes G.

    2014-01-01

    Electrochromic (EC) smart windows are able to vary their throughput of visible light and solar energy by the application of an electrical voltage and are able to provide energy efficiency and indoor comfort in buildings. Section 1 explains why this technology is important and timely by first outlining today's precarious situation concerning increasing energy use and associated effects on the world's climate, and this section also underscores the great importance of enhancing the energy efficiency of buildings by letting them function more in harmony with the environment—particularly its varying temperature—than is possible with current mainstream technologies. This same chapter also surveys recent work on the energy savings and other benefits that are possible with EC-based technologies. Section 2 then provides some notes on the history of the EC effect and its applications. Section 3 presents a generic design for the oxide-based EC devices that are most in focus for present-day applications and research. This design includes five superimposed layers with a centrally-positioned electrolyte connecting two oxide films—at least one of which having EC properties—and with transparent electrical conductors surrounding the three-layer structure in the middle. It is emphasized that this construction can be viewed as a thin-film electrical battery whose charging state is manifested as optical absorption. Also discussed are six well known hurdles for the implementation of these EC devices, as well as a number of practical constructions of EC-based smart windows. Section 4 is an in-depth discussion of various aspects of EC oxides. It begins with a literature survey for 2007–2013, which updates earlier reviews, and is followed by a general discussion of optical and electronic effects and, specifically, on charge transfer absorption in tungsten oxide. Ionic effects are then treated with foci on the inherent nanoporosity of the important EC oxides and on the

  20. Electrochromics for smart windows: Oxide-based thin films and devices

    Energy Technology Data Exchange (ETDEWEB)

    Granqvist, Claes G.

    2014-08-01

    Electrochromic (EC) smart windows are able to vary their throughput of visible light and solar energy by the application of an electrical voltage and are able to provide energy efficiency and indoor comfort in buildings. Section 1 explains why this technology is important and timely by first outlining today's precarious situation concerning increasing energy use and associated effects on the world's climate, and this section also underscores the great importance of enhancing the energy efficiency of buildings by letting them function more in harmony with the environment—particularly its varying temperature—than is possible with current mainstream technologies. This same chapter also surveys recent work on the energy savings and other benefits that are possible with EC-based technologies. Section 2 then provides some notes on the history of the EC effect and its applications. Section 3 presents a generic design for the oxide-based EC devices that are most in focus for present-day applications and research. This design includes five superimposed layers with a centrally-positioned electrolyte connecting two oxide films—at least one of which having EC properties—and with transparent electrical conductors surrounding the three-layer structure in the middle. It is emphasized that this construction can be viewed as a thin-film electrical battery whose charging state is manifested as optical absorption. Also discussed are six well known hurdles for the implementation of these EC devices, as well as a number of practical constructions of EC-based smart windows. Section 4 is an in-depth discussion of various aspects of EC oxides. It begins with a literature survey for 2007–2013, which updates earlier reviews, and is followed by a general discussion of optical and electronic effects and, specifically, on charge transfer absorption in tungsten oxide. Ionic effects are then treated with foci on the inherent nanoporosity of the important EC oxides and on the

  1. Improved wettability and adhesion of polylactic acid/chitosan coating for bio-based multilayer film development

    Energy Technology Data Exchange (ETDEWEB)

    Gartner, Hunter [School of Packaging, Michigan State University, East Lansing, Michigan (United States); Li, Yana [Mechanical Engineering College, Wuhan Polytechnic University (China); Almenar, Eva, E-mail: ealmenar@msu.edu [School of Packaging, Michigan State University, East Lansing, Michigan (United States)

    2015-03-30

    Graphical abstract: - Highlights: • Surface tension between PLA/CS blend solution and PLA film modified by MDI. • Better wettability between PLA/CS blend solution and PLA film by increasing MDI. • Increased breaking strength by increasing MDI due to the increased H-bonding. • Increased number of physical entanglements between PLA/CS coating and PLA film. • Development of a suitable bio-based multilayer film for food packaging applications. - Abstract: The objective of this study was to investigate the effect of methyldiphenyl diisocyanate (MDI) concentration (0, 0.2, 1, 2, and 3%) on the wettability and adhesion of blend solutions of poly(lactic acid) (PLA) and chitosan (CS) when coated on PLA film for development of a bio-based multi-layer film suitable for food packaging and other applications. Characterization was carried out by attenuated total reflectance infrared spectrometry (ATR-FTIR), contact angle (θ), mechanical adhesion pull-off testing, and scanning electron microscopy (SEM). The θ of the PLA/CS blend shifted to a lower value (41–35°) with increasing MDI concentration showing that the surface tension was modified between the PLA/CS blend solution and PLA film and better wettability was achieved. The increase in MDI also resulted in an increased breaking strength (228–303 kPa) due to the increased H-bonding resulting from the more urethane groups formed within the PLA/CS blend as shown by ATR-FTIR. The improved adhesion was also shown by the increased number of physical entanglements observed by SEM. It can be concluded that MDI can be used to improve wettability and adhesion between PLA/CS coating and PLA film.

  2. Using sub-micron silver-nanoparticle based films to counter biofilm formation by Gram-negative bacteria

    Science.gov (United States)

    Gillett, A. R.; Baxter, S. N.; Hodgson, S. D.; Smith, G. C.; Thomas, P. J.

    2018-06-01

    Composite films comprised of silver nanoparticles (AgNPs) grown using a low-cost straightforward chemical bath based method have been deposited on glass microscope slides to investigate their potential as a sacrificial antibacterial coating. The as-deposited films have been characterised using scanning electron microscopy (SEM) and optical profilometry. These suggested that the films were relatively uniform in coverage. Chemical composition of the AgNP films has been studied by using X-ray photoelectron spectroscopy (XPS). The XPS analysis indicated that the Ag was in a metallic form able to sustain plasmon behaviour, and that low levels of residual nanoparticle precursors were present. Particle size was characterised using transmission electron microscopy (TEM) which showed an average particle size of 10.6 nm. The effectiveness of the films as an antibacterial coating was tested against Escherichia coli. The AgNP film was determined to be effective in the killing of E. coli cells over a 24 h period when compared to equivalent samples that contained no silver. Of particular note was that only minimal bacterial growth was detected over the first 12 h of testing, up to 78.6 times less than the control samples, suggesting the film is very efficient at slowing initial biofilm formation. The use of AgNP based films that have been synthesised using a novel low-cost, low-temperature and highly upscalable method is demonstrated as a promising solution for the deployment of silver as an effective sacrifical antimicrobial coating to counter the formation of potentially hazardous Gram negative biofilms.

  3. Use of gamma-irradiation technology in the manufacture of biopolymer-based packaging films for shelf-stable foods

    International Nuclear Information System (INIS)

    Parra, Duclerc F.; Rodrigues, Juliana A.F.R.; Lugao, Ademar B.

    2005-01-01

    Gamma irradiation is an alternative method for the manufacture of sterilized packaging with increased storage stability and microbiological safety. Biopolymer-based packaging films are a potential solution to many environmental problems that have emerged from the production and accumulation of significant amounts of synthetic polymeric waste. This work was undertaken to verify the effectiveness of low-dose gamma-irradiation in obtaining biopolymer-based packaging films for shelf-stable foods. PHB polyester poly(3-hydroxybutyrate) is an interesting biodegradable polymer that has been intensely investigated as cast and sheet films, with applications in the food industry and medicine. The films obtained are, however, typically brittle, and many scientists have attempted to reduce this brittleness by blending PHB with other polymers. In the present work, PHB was blended with PEG (polyethyleneglycol) to obtain films by the casting method that were then irradiated at a dose rate of 5.72 kGy/h with a 60 Co source. Samples were melted at 200 deg. C and quenched to 0 deg. C in order to evaluate film crystallinity levels by differential scanning calorimetry (DSC). DSC analyses were performed with the samples (10 mg) under N 2 atmosphere, heating from -50 to 200 deg. C (10 deg. C min -1 ), cooling from 200 to -50 deg. C (10 deg. C min -1 ); and heating from -50 to 200 deg. C (10 deg. C min -1 ). The thermal and mechanical resistances of the films after irradiation at low doses (5, 10, 20 kGy) are discussed. Water vapour transmission decreased with increasing irradiation dose, indicating that the films' performance as water vapour barrier had improved. Critical loss of the mechanical properties was observed at 40 kGy

  4. Formulation and in vitro/in vivo evaluation of chitosan-based film forming gel containing ketoprofen.

    Science.gov (United States)

    Oh, Dong-Won; Kang, Ji-Hyun; Lee, Hyo-Jung; Han, Sang-Duk; Kang, Min-Hyung; Kwon, Yie-Hyuk; Jun, Joon-Ho; Kim, Dong-Wook; Rhee, Yun-Seok; Kim, Ju-Young; Park, Eun-Seok; Park, Chung-Woong

    2017-11-01

    The film forming gel, adhered to skin surfaces upon application and formed a film, has an advantage onto skin to provide protection and continuous drug release to the application site. This study aimed to prepare a chitosan-based film forming gel containing ketoprofen (CbFG) and to evaluate the CbFG and film from CbFG (CbFG-film). CbFG were prepared with chitosan, lactic acid and various skin permeation enhancers. The physicochemical characteristics were evaluated by texture analysis, viscometry, SEM, DSC, XRD and FT-IR. To identify the mechanism of skin permeation, in vitro skin permeation study was conducted with a Franz diffusion cell and excised SD-rat and hairless mouse dorsal skin. In vivo efficacy assessment in mono-iodoacetate (MIA)-induced rheumatoid arthritis animal model was also conducted. CbFG was successfully prepared and, after applying CbFG to the excised rat dorsal skin, the CbFG-film was also formed well. The physicochemical characteristics of CbFG and CbFG-film could be explained by the grafting of oleic acid onto chitosan in the absence of catalysts. In addition, CbFG containing oleic acid had a higher skin permeation rate in comparison with any other candidate enhancers. The in vivo efficacy study also confirmed significant anti-inflammatory and analgesic effects. Consequently, we report the successful preparation of chitosan-based film forming gel containing ketoprofen with excellent mechanical properties, skin permeation and anti-inflammatory and analgesic effects.

  5. Use of gamma-irradiation technology in the manufacture of biopolymer-based packaging films for shelf-stable foods

    Science.gov (United States)

    Parra, Duclerc F.; Rodrigues, Juliana A. F. R.; Lugão, Ademar B.

    2005-07-01

    Gamma irradiation is an alternative method for the manufacture of sterilized packaging with increased storage stability and microbiological safety. Biopolymer-based packaging films are a potential solution to many environmental problems that have emerged from the production and accumulation of significant amounts of synthetic polymeric waste. This work was undertaken to verify the effectiveness of low-dose gamma-irradiation in obtaining biopolymer-based packaging films for shelf-stable foods. PHB polyester poly(3-hydroxybutyrate) is an interesting biodegradable polymer that has been intensely investigated as cast and sheet films, with applications in the food industry and medicine. The films obtained are, however, typically brittle, and many scientists have attempted to reduce this brittleness by blending PHB with other polymers. In the present work, PHB was blended with PEG (polyethyleneglycol) to obtain films by the casting method that were then irradiated at a dose rate of 5.72 kGy/h with a 60Co source. Samples were melted at 200 °C and quenched to 0 °C in order to evaluate film crystallinity levels by differential scanning calorimetry (DSC). DSC analyses were performed with the samples (10 mg) under N2 atmosphere, heating from -50 to 200 °C (10 °C min-1), cooling from 200 to -50 °C (10 °C min-1); and heating from -50 to 200 °C (10 °C min-1). The thermal and mechanical resistances of the films after irradiation at low doses (5, 10, 20 kGy) are discussed. Water vapour transmission decreased with increasing irradiation dose, indicating that the films' performance as water vapour barrier had improved. Critical loss of the mechanical properties was observed at 40 kGy.

  6. Improved wettability and adhesion of polylactic acid/chitosan coating for bio-based multilayer film development

    International Nuclear Information System (INIS)

    Gartner, Hunter; Li, Yana; Almenar, Eva

    2015-01-01

    Graphical abstract: - Highlights: • Surface tension between PLA/CS blend solution and PLA film modified by MDI. • Better wettability between PLA/CS blend solution and PLA film by increasing MDI. • Increased breaking strength by increasing MDI due to the increased H-bonding. • Increased number of physical entanglements between PLA/CS coating and PLA film. • Development of a suitable bio-based multilayer film for food packaging applications. - Abstract: The objective of this study was to investigate the effect of methyldiphenyl diisocyanate (MDI) concentration (0, 0.2, 1, 2, and 3%) on the wettability and adhesion of blend solutions of poly(lactic acid) (PLA) and chitosan (CS) when coated on PLA film for development of a bio-based multi-layer film suitable for food packaging and other applications. Characterization was carried out by attenuated total reflectance infrared spectrometry (ATR-FTIR), contact angle (θ), mechanical adhesion pull-off testing, and scanning electron microscopy (SEM). The θ of the PLA/CS blend shifted to a lower value (41–35°) with increasing MDI concentration showing that the surface tension was modified between the PLA/CS blend solution and PLA film and better wettability was achieved. The increase in MDI also resulted in an increased breaking strength (228–303 kPa) due to the increased H-bonding resulting from the more urethane groups formed within the PLA/CS blend as shown by ATR-FTIR. The improved adhesion was also shown by the increased number of physical entanglements observed by SEM. It can be concluded that MDI can be used to improve wettability and adhesion between PLA/CS coating and PLA film

  7. Multifunctional microstructured polymer films for boosting solar power generation of silicon-based photovoltaic modules.

    Science.gov (United States)

    Leem, Jung Woo; Choi, Minkyu; Yu, Jae Su

    2015-02-04

    We propose two-dimensional periodic conical micrograting structured (MGS) polymer films as a multifunctional layer (i.e., light harvesting and self-cleaning) at the surface of outer polyethylene terephthalate (PET) cover-substrates for boosting the solar power generation in silicon (Si)-based photovoltaic (PV) modules. The surface of ultraviolet-curable NOA63 MGS polymer films fabricated by the soft imprint lithography exhibits a hydrophobic property with water contact angle of ∼121° at no inclination and dynamic advancing/receding water contact angles of ∼132°/111° at the inclination angle of 40°, respectively, which can remove dust particles or contaminants on the surface of PV modules in real outdoor environments (i.e., self-cleaning). The NOA63 MGS film coated on the bare PET leads to the reduction of reflection as well as the enhancement of both the total and diffuse transmissions at wavelengths of 300-1100 nm, indicating lower solar weighted reflectance (RSW) of ∼8.2%, higher solar weighted transmittance (TSW) of ∼93.1%, and considerably improved average haze ratio (HAvg) of ∼88.3% as compared to the bare PET (i.e., RSW ≈ 13.5%, TSW ≈ 86.9%, and HAvg ≈ 9.1%), respectively. Additionally, it shows a relatively good durability at temperatures of ≤160 °C. The resulting Si PV module with the NOA63 MGS/PET has an enhanced power conversion efficiency (PCE) of 13.26% (cf., PCE = 12.55% for the reference PV module with the bare PET) due to the mainly improved short circuit current from 49.35 to 52.01 mA, exhibiting the PCE increment percentage of ∼5.7%. For light incident angle-dependent PV module current-voltage characteristics, superior solar energy conversion properties are also obtained in a broad angle range of 10-80°.

  8. Physiologically-based pharmacokinetic model of vaginally administered dapivirine ring and film formulations.

    Science.gov (United States)

    Kay, Katherine; Shah, Dhaval K; Rohan, Lisa; Bies, Robert

    2018-05-01

    A physiologically-based pharmacokinetic (PBPK) model of the vaginal space was developed with the aim of predicting concentrations in the vaginal and cervical space. These predictions can be used to optimize the probability of success of vaginally administered dapivirine (DPV) for HIV prevention. We focus on vaginal delivery using either a ring or film. A PBPK model describing the physiological structure of the vaginal tissue and fluid was defined mathematically and implemented in MATLAB. Literature reviews provided estimates for relevant physiological and physiochemical parameters. Drug concentration-time profiles were simulated in luminal fluids, vaginal tissue and plasma after administration of ring or film. Patient data were extracted from published clinical trials and used to test model predictions. The DPV ring simulations tested the two dosing regimens and predicted PK profiles and area under the curve of luminal fluids (29 079 and 33 067 mg h l -1 in groups A and B, respectively) and plasma (0.177 and 0.211 mg h l -1 ) closely matched those reported (within one standard deviation). While the DPV film study reported drug concentration at only one time point per patient, our simulated profiles pass through reported concentration range. HIV is a major public health issue and vaginal microbicides have the potential to provide a crucial, female-controlled option for protection. The PBPK model successfully simulated realistic representations of drug PK. It provides a reliable, inexpensive and accessible platform where potential effectiveness of new compounds and the robustness of treatment modalities for pre-exposure prophylaxis can be evaluated. © 2018 The Authors. British Journal of Clinical Pharmacology published by John Wiley & Sons Ltd on behalf of British Pharmacological Society.

  9. High oxygen nanocomposite barrier films based on xylan and nanocrystalline cellulose

    Science.gov (United States)

    Amit Saxena; Thomas J. Elder; Jeffrey Kenvin; Arthur J. Ragauskas

    2010-01-01

    The goal of this work is to produce nanocomposite film with low oxygen permeability by casting an aqueous solution containing xylan, sorbitol and nanocrystalline cellulose. The morphology of the resulting nanocomposite films was examined by scanning electron microscopy and atomic force microscopy which showed that control films containing xylan and sorbitol had a more...

  10. Development and characterization of edible films based on gluten from semi-hard and soft Brazilian wheat flours (development of films based on gluten from wheat flours Desenvolvimento e caracterização de filmes comestíveis de glúten de farinhas fortes e fracas de trigos brasileiros

    Directory of Open Access Journals (Sweden)

    Patrícia Sayuri Tanada-Palmu

    2003-08-01

    Full Text Available Edible films based on gluten from four types of Brazilian wheat gluten (2 "semi-hard" and 2 "soft" were prepared and mechanical and barrier properties were compared with those of wheat gluten films with vital gluten. Water vapor, oxygen permeability, tensile strength and percent elongation at break, solubility in water and surface morphology were measured. The films from "semi-hard" wheat flours showed similar water vapor permeability and solubility in water to films from vital gluten and better tensile strength than the films from "soft" and vital gluten. The films from vital gluten had higher elongation at break and oxygen permeability and also lower solubility in water than the films from the Brazilian wheat "soft" flours. In spite of the vital gluten showed greater mechanical resistance, desirable for the bakery products, for the purpose of developing gluten films Brazilian "semi-hard" wheat flours can be used instead of vital gluten, since they showed similar barrier and mechanical properties.Filmes à base de glúten de quatro tipos de farinhas de trigo brasileiras (2 "semi-fortes " e 2 "fracas" foram preparados e suas propriedades mecânicas e de barreira foram comparadas com filmes com glúten vital (comercial. Permeabilidade ao vapor d'água e oxigênio, resistência à tração, porcentagem de elongação na ruptura, solubilidade em água e morfologia de superfície foram medidas. Filmes de glúten das farinhas "semi-fortes" mostraram similar permeabilidade ao vapor d'água e solubilidade em água em comparação aos filmes de glúten vital e melhor resistência à tração do que os filmes das farinhas "fracas" e glúten vital. O filme de glúten vital apresentou maior elongação na ruptura e permeabilidade ao oxigênio do que os filmes das farinhas brasileiras e ainda mais baixa solubilidade que as farinhas fracas. Apesar do glúten vital ter uma grande resistência mecânica, desejável para produtos de panificação, para o prop

  11. A novel flexible capacitive touch pad based on graphene oxide film

    Science.gov (United States)

    Tian, He; Yang, Yi; Xie, Dan; Ren, Tian-Ling; Shu, Yi; Zhou, Chang-Jian; Sun, Hui; Liu, Xuan; Zhang, Cang-Hai

    2013-01-01

    Recently, graphene oxide (GO) supercapacitors with ultra-high energy densities have received significant attention. In addition to energy storage, GO capacitors might also have broad applications in renewable energy engineering, such as vibration and sound energy harvesting. Here, we experimentally create a macroscopic flexible capacitive touch pad based on GO film. An obvious touch ``ON'' to ``OFF'' voltage ratio up to ~60 has been observed. Moreover, we tested the capacitor structure on both flat and curved surfaces and it showed high response sensitivity under fast touch rates. Collectively, our results raise the exciting prospect that the realization of macroscopic flexible keyboards with large-area graphene based materials is technologically feasible, which may open up important applications in control and interface design for solar cells, speakers, supercapacitors, batteries and MEMS systems.

  12. Thermoelectric Transport by Surface States in Bi2Se3-Based Topological Insulator Thin Films

    International Nuclear Information System (INIS)

    Li Long-Long; Xu Wen

    2015-01-01

    We develop a tractable theoretical model to investigate the thermoelectric (TE) transport properties of surface states in topological insulator thin films (TITFs) of Bi 2 Se 3 at room temperature. The hybridization between top and bottom surface states in the TITF plays a significant role. With the increasing hybridization-induced surface gap, the electrical conductivity and electron thermal conductivity decrease while the Seebeck coefficient increases. This is due to the metal-semiconductor transition induced by the surface-state hybridization. Based on these TE transport coefficients, the TE figure-of-merit ZT is evaluated. It is shown that ZT can be greatly improved by the surface-state hybridization. Our theoretical results are pertinent to the exploration of the TE transport properties of surface states in TITFs and to the potential application of Bi 2 Se 3 -based TITFs as high-performance TE materials and devices. (paper)

  13. Membrane and Films Based on Novel Crown-Containing Dyes as Promising Chemosensoring Materials

    Directory of Open Access Journals (Sweden)

    Sergei Yu. Zaitsev

    2010-12-01

    Full Text Available This paper discusses several works on supramolecular systems such as monolayer and multilayer, polymer films of various crown-containing dyes, surface-active monomers and polymers. Design, production and investigation of the membrane nanostructures based on crown ethers is a rapidly developing field at the “junction” of materials sciences and nanotechnology. These nanostructures can serve as convenient models for studying the self-organization and molecular recognition processes at interfaces that are typical for biomembranes. Based on the results obtained for such structures by absorption and fluorescence spectroscopy, atomic force and Brewster-angle microscopy, surface pressure and surface potential isotherm measurements, the possibility of developing micro- and nanomaterials possessing a set of specified properties (including chemosensor, photochromic and photorefractive materials is demonstrated.

  14. Modified hyperbolic sine model for titanium dioxide-based memristive thin films

    Science.gov (United States)

    Abu Bakar, Raudah; Syahirah Kamarozaman, Nur; Fazlida Hanim Abdullah, Wan; Herman, Sukreen Hana

    2018-03-01

    Since the emergence of memristor as the newest fundamental circuit elements, studies on memristor modeling have been evolved. To date, the developed models were based on the linear model, linear ionic drift model using different window functions, tunnelling barrier model and hyperbolic-sine function based model. Although using hyperbolic-sine function model could predict the memristor electrical properties, the model was not well fitted to the experimental data. In order to improve the performance of the hyperbolic-sine function model, the state variable equation was modified. On the one hand, the addition of window function cannot provide an improved fitting. By multiplying the Yakopcic’s state variable model to Chang’s model on the other hand resulted in the closer agreement with the TiO2 thin film experimental data. The percentage error was approximately 2.15%.

  15. A novel flexible capacitive touch pad based on graphene oxide film.

    Science.gov (United States)

    Tian, He; Yang, Yi; Xie, Dan; Ren, Tian-Ling; Shu, Yi; Zhou, Chang-Jian; Sun, Hui; Liu, Xuan; Zhang, Cang-Hai

    2013-02-07

    Recently, graphene oxide (GO) supercapacitors with ultra-high energy densities have received significant attention. In addition to energy storage, GO capacitors might also have broad applications in renewable energy engineering, such as vibration and sound energy harvesting. Here, we experimentally create a macroscopic flexible capacitive touch pad based on GO film. An obvious touch "ON" to "OFF" voltage ratio up to ∼60 has been observed. Moreover, we tested the capacitor structure on both flat and curved surfaces and it showed high response sensitivity under fast touch rates. Collectively, our results raise the exciting prospect that the realization of macroscopic flexible keyboards with large-area graphene based materials is technologically feasible, which may open up important applications in control and interface design for solar cells, speakers, supercapacitors, batteries and MEMS systems.

  16. A new transmission methodology for quality assurance in radiotherapy based on radiochromic film measurements

    Science.gov (United States)

    do Amaral, Leonardo L.; Pavoni, Juliana F.; Sampaio, Francisco; Netto, Thomaz Ghilardi

    2015-01-01

    Despite individual quality assurance (QA) being recommended for complex techniques in radiotherapy (RT) treatment, the possibility of errors in dose delivery during therapeutic application has been verified. Therefore, it is fundamentally important to conduct in vivo QA during treatment. This work presents an in vivo transmission quality control methodology, using radiochromic film (RCF) coupled to the linear accelerator (linac) accessory holder. This QA methodology compares the dose distribution measured by the film in the linac accessory holder with the dose distribution expected by the treatment planning software. The calculated dose distribution is obtained in the coronal and central plane of a phantom with the same dimensions of the acrylic support used for positioning the film but in a source‐to‐detector distance (SDD) of 100 cm, as a result of transferring the IMRT plan in question with all the fields positioned with the gantry vertically, that is, perpendicular to the phantom. To validate this procedure, first of all a Monte Carlo simulation using PENELOPE code was done to evaluate the differences between the dose distributions measured by the film in a SDD of 56.8 cm and 100 cm. After that, several simple dose distribution tests were evaluated using the proposed methodology, and finally a study using IMRT treatments was done. In the Monte Carlo simulation, the mean percentage of points approved in the gamma function comparing the dose distribution acquired in the two SDDs were 99.92%±0.14%. In the simple dose distribution tests, the mean percentage of points approved in the gamma function were 99.85%±0.26% and the mean percentage differences in the normalization point doses were −1.41%. The transmission methodology was approved in 24 of 25 IMRT test irradiations. Based on these results, it can be concluded that the proposed methodology using RCFs can be applied for in vivo QA in RT treatments. PACS number: 87.55.Qr, 87.55.km, 87.55.N‐ PMID

  17. Corrosion in low dielectric constant Si-O based thin films: Buffer concentration effects

    International Nuclear Information System (INIS)

    Zeng, F. W.; Lane, M. W.; Gates, S. M.

    2014-01-01

    Organosilicate glass (OSG) is often used as an interlayer dielectric (ILD) in high performance integrated circuits. OSG is a brittle material and prone to stress-corrosion cracking reminiscent of that observed in bulk glasses. Of particular concern are chemical-mechanical planarization techniques and wet cleans involving solvents commonly encountered in microelectronics fabrication where the organosilicate film is exposed to aqueous environments. Previous work has focused on the effect of pH, surfactant, and peroxide concentration on the subcritical crack growth of these films. However, little or no attention has focused on the effect of the conjugate acid/base concentration in a buffer. Accordingly, this work examines the “strength” of the buffer solution in both acidic and basic environments. The concentration of the buffer components is varied keeping the ratio of acid/base and therefore pH constant. In addition, the pH was varied by altering the acid/base ratio to ascertain any additional effect of pH. Corrosion tests were conducted with double-cantilever beam fracture mechanics specimens and fracture paths were verified with ATR-FTIR. Shifts in the threshold fracture energy, the lowest energy required for bond rupture in the given environment, G TH , were found to shift to lower values as the concentration of the base in the buffer increased. This effect was found to be much larger than the effect of the hydroxide ion concentration in unbuffered solutions. The results are rationalized in terms of the salient chemical bond breaking process occurring at the crack tip and modeled in terms of the chemical potential of the reactive species

  18. Transparent conductive zinc-oxide-based films grown at low temperature by mist chemical vapor deposition

    Energy Technology Data Exchange (ETDEWEB)

    Shirahata, Takahiro [New Energy and Environmental Business Division, Toshiba Mitsubishi-Electric Industrial Systems Corporation, Kobe International Business Center (KIBC) 509, 5-5-2 Minatojima-Minami, Chuo-Ku, Kobe 650-0047 (Japan); Kawaharamura, Toshiyuki [Research Institute, Kochi University of Technology, Kami, Kochi 780-8502 (Japan); School of Systems Engineering, Kochi University of Technology, Kami, Kochi 780-8502 (Japan); Fujita, Shizuo, E-mail: fujitasz@kuee.kyoto-u.ac.jp [Photonics and Electronics Science and Engineering Center, Kyoto University, Katsura, Nishikyo-ku, Kyoto 615-8520 (Japan); Orita, Hiroyuki [New Energy and Environmental Business Division, Toshiba Mitsubishi-Electric Industrial Systems Corporation, Kobe International Business Center (KIBC) 509, 5-5-2 Minatojima-Minami, Chuo-Ku, Kobe 650-0047 (Japan)

    2015-12-31

    Atmospheric pressure mist chemical vapor deposition (Mist–CVD) systems have been developed to grow zinc-oxide-based (ZnO-based) transparent conductive oxide (TCO) films. Low-resistive aluminum-doped ZnO (AZO) TCOs, showing resistivity of the order on 10{sup −4} Ωcm, previously were grown using a safe source material zinc acetate [Zn(ac){sub 2}], at a growth temperature as high as 500 °C. To grow superior TCOs at lower temperatures, we proposed the addition of NH{sub 3} to accelerate the reaction of acetylacetonate compounds. As the result, we could grow gallium-doped ZnO (GZO) TCOs with a resistivity of 2.7 × 10{sup −3} Ω cm and transmittance higher than 90% at 300 °C by using zinc acetylacetonate [Zn(acac){sub 2}] as the Zn source. To grow boron-doped ZnO (BZO) TCOs at a lower growth temperature of 200 °C, we used boron doping along with a toluene solution of diethylzinc (DEZ), that maintained high reactivity without being flammable. These BZO TCOs showed a resistivity of 1.5 × 10{sup −3} Ω cm and transmittance higher than 90%, despite the use of a non-vacuum-based open-air technology. - Highlights: • Introduction of Mist–CVD as a non-vacuum-based, safe, and cost-effective growth technology • Process evolution of the growth technology to lower the growth temperature. • Achievement of low resistive ZnO films at 200oC.

  19. Transparent conductive zinc-oxide-based films grown at low temperature by mist chemical vapor deposition

    International Nuclear Information System (INIS)

    Shirahata, Takahiro; Kawaharamura, Toshiyuki; Fujita, Shizuo; Orita, Hiroyuki

    2015-01-01

    Atmospheric pressure mist chemical vapor deposition (Mist–CVD) systems have been developed to grow zinc-oxide-based (ZnO-based) transparent conductive oxide (TCO) films. Low-resistive aluminum-doped ZnO (AZO) TCOs, showing resistivity of the order on 10"−"4 Ωcm, previously were grown using a safe source material zinc acetate [Zn(ac)_2], at a growth temperature as high as 500 °C. To grow superior TCOs at lower temperatures, we proposed the addition of NH_3 to accelerate the reaction of acetylacetonate compounds. As the result, we could grow gallium-doped ZnO (GZO) TCOs with a resistivity of 2.7 × 10"−"3 Ω cm and transmittance higher than 90% at 300 °C by using zinc acetylacetonate [Zn(acac)_2] as the Zn source. To grow boron-doped ZnO (BZO) TCOs at a lower growth temperature of 200 °C, we used boron doping along with a toluene solution of diethylzinc (DEZ), that maintained high reactivity without being flammable. These BZO TCOs showed a resistivity of 1.5 × 10"−"3 Ω cm and transmittance higher than 90%, despite the use of a non-vacuum-based open-air technology. - Highlights: • Introduction of Mist–CVD as a non-vacuum-based, safe, and cost-effective growth technology • Process evolution of the growth technology to lower the growth temperature. • Achievement of low resistive ZnO films at 200oC.

  20. Electronic and optical device applications of hollow cathode plasma assisted atomic layer deposition based GaN thin films

    International Nuclear Information System (INIS)

    Bolat, Sami; Tekcan, Burak; Ozgit-Akgun, Cagla; Biyikli, Necmi; Okyay, Ali Kemal

    2015-01-01

    Electronic and optoelectronic devices, namely, thin film transistors (TFTs) and metal–semiconductor–metal (MSM) photodetectors, based on GaN films grown by hollow cathode plasma-assisted atomic layer deposition (PA-ALD) are demonstrated. Resistivity of GaN thin films and metal-GaN contact resistance are investigated as a function of annealing temperature. Effect of the plasma gas and postmetallization annealing on the performances of the TFTs as well as the effect of the annealing on the performance of MSM photodetectors are studied. Dark current to voltage and responsivity behavior of MSM devices are investigated as well. TFTs with the N 2 /H 2 PA-ALD based GaN channels are observed to have improved stability and transfer characteristics with respect to NH 3 PA-ALD based transistors. Dark current of the MSM photodetectors is suppressed strongly after high-temperature annealing in N 2 :H 2 ambient

  1. Fabrication of Cu{sub 2}ZnSn(S,Se){sub 4} (CZTSSe) absorber films based on solid-phase synthesis and blade coating processes

    Energy Technology Data Exchange (ETDEWEB)

    Ma, Ruixin, E-mail: mrx_601@126.com [School of Metallurgy and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Beijing Key Laboratory of Special Melting and Preparation of High-end Metal Materials, Beijing 100083 (China); Yang, Fan; Li, Shina; Zhang, Xiaoyong; Li, Xiang; Cheng, Shiyao; Liu, Zilin [School of Metallurgy and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083 (China)

    2016-04-15

    Graphical abstract: - Highlights: • Pure CZTS nano-crystalline have been prepared based on solid-phase synthesis. • A simple and modified doctor blade process followed by a selenization technique was utilized to fabricate CZTSSe absorber films. • Comparative studies on the properties of CZTS and CZTSSe absorber films have been investigated. • The band gap of CZTSSe absorber films was determined to be 1.26 eV. - Abstract: CZTSSe is an important earth abundant collection of materials for the development of low cost and high efficiency thin film solar cells. This work developed a simple non-vacuum-based route to fabricate CZTSSe absorber films. This was demonstrated by first synthesizing Cu{sub 2}ZnSnS{sub 4} (CZTS) nano-crystalline based on solid-phase synthesis. Then a stable colloidal ink composed of CZTS nano-crystalline was blade coated on Mo-coated substrates followed by an annealing process under Ar atmosphere. After CZTS films formation, the films were sintered into CZTSSe absorber films by exposing them under Selenium vapor. The formation of a kesterite type CZTS was confirmed using X-ray diffraction and Raman scattering measurements. The band gap of CZTSSe absorber films was determined to be 1.26 eV, which was appropriate for use as an absorber layer in thin film solar cells. The CZTSSe absorber films showed a good photovoltatic performance, demonstrating this simple approach had great potential for CZTSSe solar cell production.

  2. Development and surface characterization of a glucose biosensor based on a nanocolumnar ZnO film

    Energy Technology Data Exchange (ETDEWEB)

    Rodrigues, A., E-mail: adriana.rodrigues@partner.kit.edu [Instituto de Física − UFRGS, P.O. Box 15051, 91501-970 Porto Alegre, RS (Brazil); Castegnaro, M.V. [Instituto de Física − UFRGS, P.O. Box 15051, 91501-970 Porto Alegre, RS (Brazil); Arguello, J.; Alves, M.C.M. [Instituto de Química − UFRGS, P.O. Box 15003, 91501-970 Porto Alegre, RS (Brazil); Morais, J., E-mail: jonder@if.ufrgs.br [Instituto de Física − UFRGS, P.O. Box 15051, 91501-970 Porto Alegre, RS (Brazil)

    2017-04-30

    Highlights: • Glucose biosensor based on self-assembled nanocolumnar ZnO deposited on stainless steel. • XPS applied to investigate the GOx immobilization on the ZnO nanocolumns surface. • Observable chemical shifts on O1s and Zn2p corroborates enzime immobilization. - Abstract: Highly oriented nanostructured ZnO films were grown on the surface of stainless steel plates (ZnO/SS) by chemical bath deposition (CBD). The films consisted of vertically aligned ZnO nanocolumns, ∼1 μm long and ∼80 nm wide, as observed by SEM (scanning electron microscopy) and FIB (focused ion beam). XRD (X-ray diffraction) confirmed the c-axis preferred orientation of the ZnO columns, which were functionalized with the glucose oxidase (GOx) enzyme into a biosensor of glucose. The electrochemical response studied by CV (cyclic voltammetry) proved that the biosensor was capable of detecting glucose from 1.5 up to 16 mM concentration range. XPS (X-ray photoelectron spectroscopy) analysis, excited with synchrotron radiation, probed the atom specific chemical environment at the electrode’s surface and shed some light on the nature of the ZnO-GOx interaction.

  3. Flexible solid-state supercapacitors based on three-dimensional graphene hydrogel films.

    Science.gov (United States)

    Xu, Yuxi; Lin, Zhaoyang; Huang, Xiaoqing; Liu, Yuan; Huang, Yu; Duan, Xiangfeng

    2013-05-28

    Flexible solid-state supercapacitors are of considerable interest as mobile power supply for future flexible electronics. Graphene or carbon nanotubes based thin films have been used to fabricate flexible solid-state supercapacitors with high gravimetric specific capacitances (80-200 F/g), but usually with a rather low overall or areal specific capacitance (3-50 mF/cm(2)) due to the ultrasmall electrode thickness (typically a few micrometers) and ultralow mass loading, which is not desirable for practical applications. Here we report the exploration of a three-dimensional (3D) graphene hydrogel for the fabrication of high-performance solid-state flexible supercapacitors. With a highly interconnected 3D network structure, graphene hydrogel exhibits exceptional electrical conductivity and mechanical robustness to make it an excellent material for flexible energy storage devices. Our studies demonstrate that flexible supercapacitors with a 120 μm thick graphene hydrogel thin film can exhibit excellent capacitive characteristics, including a high gravimetric specific capacitance of 186 F/g (up to 196 F/g for a 42 μm thick electrode), an unprecedented areal specific capacitance of 372 mF/cm(2) (up to 402 mF/cm(2) for a 185 μm thick electrode), low leakage current (10.6 μA), excellent cycling stability, and extraordinary mechanical flexibility. This study demonstrates the exciting potential of 3D graphene macrostructures for high-performance flexible energy storage devices.

  4. Antimicrobial thin films based on ayurvedic plants extracts embedded in a bioactive glass matrix

    Science.gov (United States)

    Floroian, L.; Ristoscu, C.; Candiani, G.; Pastori, N.; Moscatelli, M.; Mihailescu, N.; Negut, I.; Badea, M.; Gilca, M.; Chiesa, R.; Mihailescu, I. N.

    2017-09-01

    Ayurvedic medicine is one of the oldest medical systems. It is an example of a coherent traditional system which has a time-tested and precise algorithm for medicinal plant selection, based on several ethnopharmacophore descriptors which knowledge endows the user to adequately choose the optimal plant for the treatment of certain pathology. This work aims for linking traditional knowledge with biomedical science by using traditional ayurvedic plants extracts with antimicrobial effect in form of thin films for implant protection. We report on the transfer of novel composites from bioactive glass mixed with antimicrobial plants extracts and polymer by matrix-assisted pulsed laser evaporation into uniform thin layers onto stainless steel implant-like surfaces. The comprehensive characterization of the deposited films was performed by complementary analyses: Fourier transformed infrared spectroscopy, glow discharge optical emission spectroscopy, scanning electron microscopy, atomic force microscopy, electrochemical impedance spectroscopy, UV-VIS absorption spectroscopy and antimicrobial tests. The results emphasize upon the multifunctionality of these coatings which allow to halt the leakage of metal and metal oxides into the biological fluids and eventually to inner organs (by polymer use), to speed up the osseointegration (due to the bioactive glass use), to exert antimicrobial effects (by ayurvedic plants extracts use) and to decrease the implant price (by cheaper stainless steel use).

  5. Fabrication of Thermoelectric Sensor and Cooling Devices Based on Elaborated Bismuth-Telluride Alloy Thin Films

    Directory of Open Access Journals (Sweden)

    Abdellah Boulouz

    2014-01-01

    Full Text Available The principal motivation of this work is the development and realization of smart cooling and sensors devices based on the elaborated and characterized semiconducting thermoelectric thin film materials. For the first time, the details design of our sensor and the principal results are published. Fabrication and characterization of Bi/Sb/Te (BST semiconducting thin films have been successfully investigated. The best values of Seebeck coefficient (α(T at room temperature for Bi2Te3, and (Bi1−xSbx2Te3 with x = 0.77 are found to be −220 µV/K and +240 µV/K, respectively. Fabrication and evaluation of performance devices are reported. 2.60°C of cooling of only one Peltier module device for an optimal current of Iopt=2.50 mA is obtained. The values of temperature measured by infrared camera, by simulation, and those measured by the integrated and external thermocouple are reported. A sensitivity of the sensors of 5 mV Torr−1 mW−1 for the pressure sensor has been found with a response time of about 600 ms.

  6. Biomimetic ELISA detection of malachite green based on molecularly imprinted polymer film.

    Science.gov (United States)

    Li, Lu; Peng, Ai-Hong; Lin, Zheng-Zhong; Zhong, Hui-Ping; Chen, Xiao-Mei; Huang, Zhi-Yong

    2017-08-15

    A highly selective and sensitive enzyme-linked immunosorbent assay (ELISA) was developed for the detection of malachite green (MG) using a molecularly imprinted polymer (MIP) film as bionic antibody. The MIP film, based on the self-polymerization of dopamine, was fabricated on the surfaces of a 96-well microplate. It showed specific recognition for MG in aqueous solution. A direct competitive ELISA method was established with the sensitivity reaching 10.31μgL -1 and the detection limit being 0.3μgL -1 . The cross-reactivity of two structural analogues to MG was less than 10%. The average recovery tested by MG standard spiking was 88.8% for bass and 90.4% for water, and the relative standard deviations were less than 3.6%. All the above results indicated that the developed method could be used to detect MG in fish and water samples rapidly, specifically and accurately. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Transparent electrode designs based on optimal nano-patterning of metallic films

    KAUST Repository

    Catrysse, Peter B.

    2010-09-10

    Transparent conductive electrodes are critical to the operation of optoelectronic devices, such as photovoltaic cells and light emitting diodes. Effective electrodes need to combine excellent electrical and optical properties. Metal oxides, such as indium tin oxide, are commonly used. There is substantial interest in replacing them, however, motivated by practical problems and recent discoveries regarding the optics of nano-patterned metals. When designing nano-patterned metallic films for use as electrodes, one needs to account for both optical and electrical properties. In general, it is insufficient to optimize nano-structured films based upon optical properties alone, since structural variations will also affect the electrical properties. In this work, we investigate the need for simultaneous optical and electrical performance by analyzing the optical properties of a class of nano-patterned metallic electrodes that is obtained by a constant-sheet-resistance transformation. Within such a class the electrical and optical properties can be separated, i.e., the sheet resistance can be kept constant and the transmittance can be optimized independently. For simple one-dimensional periodic patterns with constant sheet-resistance, we find a transmission maximum (polarization-averaged) when the metal sections are narrow (< 40 nm, ~ 10% metal fill-factor) and tall (> 100 nm). Our design carries over to more complex two-dimensional (2D) patterns. This is significant as there are no previous reports regarding numerical studies on the optical and electrical properties of 2D nano-patterns in the context of electrode design.

  8. Flow and heat transfer in water based liquid film fluids dispensed with graphene nanoparticles

    Science.gov (United States)

    Zuhra, Samina; Khan, Noor Saeed; Khan, Muhammad Altaf; Islam, Saeed; Khan, Waris; Bonyah, Ebenezer

    2018-03-01

    The unsteady flow and heat transfer characteristics of electrically conducting water based thin liquid film non-Newtonian (Casson and Williamson) nanofluids dispensed with graphene nanoparticles past a stretching sheet are considered in the presence of transverse magnetic field and non-uniform heat source/sink. Embedding the graphene nanoparticles effectively amplifies the thermal conductivity of Casson and Williamson nanofluids. Ordinary differential equations together with the boundary conditions are obtained through similarity variables from the governing equations of the problem, which are solved by the HAM (Homotopy Analysis Method). The solution is expressed through graphs and illustrated which show the influences of all the parameters. The convergence of the HAM solution for the linear operators is obtained. Favorable comparison with previously published research paper is performed to show the correlation for the present work. Skin friction coefficient and Nusselt number are presented through Tables and graphs which show the validation for the achieved results demonstrating that the thin liquid films results from this study are in close agreement with the results reported in the literature. Results achieved by HAM and residual errors are evaluated numerically, given in Tables and also depicted graphically which show the accuracy of the present work.

  9. Flow and heat transfer in water based liquid film fluids dispensed with graphene nanoparticles

    Directory of Open Access Journals (Sweden)

    Samina Zuhra

    2018-03-01

    Full Text Available The unsteady flow and heat transfer characteristics of electrically conducting water based thin liquid film non-Newtonian (Casson and Williamson nanofluids dispensed with graphene nanoparticles past a stretching sheet are considered in the presence of transverse magnetic field and non-uniform heat source/sink. Embedding the graphene nanoparticles effectively amplifies the thermal conductivity of Casson and Williamson nanofluids. Ordinary differential equations together with the boundary conditions are obtained through similarity variables from the governing equations of the problem, which are solved by the HAM (Homotopy Analysis Method. The solution is expressed through graphs and illustrated which show the influences of all the parameters. The convergence of the HAM solution for the linear operators is obtained. Favorable comparison with previously published research paper is performed to show the correlation for the present work. Skin friction coefficient and Nusselt number are presented through Tables and graphs which show the validation for the achieved results demonstrating that the thin liquid films results from this study are in close agreement with the results reported in the literature. Results achieved by HAM and residual errors are evaluated numerically, given in Tables and also depicted graphically which show the accuracy of the present work. Keywords: Graphene nanoparticles, MHD, Casson and Williamson nanofluids, Stretching sheet, Skin friction coefficient, Nusselt number, Residual errors, Homotopy Analysis Method

  10. Thin-Film LSCs Based on PMMA Nanohybrid Coatings: Device Optimization and Outdoor Performance

    Directory of Open Access Journals (Sweden)

    S. M. El-Bashir

    2013-01-01

    Full Text Available This study concerns the design optimization of thin-film luminescent solar concentrators (TLSCs based on polymethylmethacrylate (PMMA/silica nanohybrid films doped with coumarin dyestuffs specialized in coloring plastics. Two designs of TLSCs had been prepared and characterized. The first consists of a transparent nanohybrid layer coated on a fluorescent PMMA substrate. The second design is the ordinary configuration in which fluorescent nanohybrid layer is coated on a transparent PMMA substrate. The investigation of the spectral properties and efficiency parameters recommended the best solar energy conversion efficiency for the second design. The outdoor performance of optimized TLSC was also evaluated under clear sky conditions of Riyadh city, and the hourly values of the optical efficiency, ηopt, were calculated for one year. The best performance was achieved in summer since the short circuit current for PV cell was doubled after being attached to TLSC and the value of ηopt reached 40% which is higher than other values recorded before due to the abundant solar energy potential in the Arabian Peninsula.

  11. Surface plasmon resonance based fiber optic detection of chlorine utilizing polyvinylpyrolidone supported zinc oxide thin films.

    Science.gov (United States)

    Tabassum, Rana; Gupta, Banshi D

    2015-03-21

    A highly sensitive chlorine sensor for an aqueous medium is fabricated using an optical fiber surface plasmon resonance (OFSPR) system. An OFSPR-based chlorine sensor is designed with a multilayer-type platform by zinc oxide (ZnO) and polyvinylpyrollidone (PVP) film morphology manipulations. Among all the methodologies of transduction reported in the field of solid state chemical and biochemical sensing, our attention is focused on the Kretschmann configuration optical fiber sensing technique using the mechanism of surface plasmon resonance. The optical fiber surface plasmon resonance (SPR) chlorine sensor is developed using a multimode optical fiber with the PVP-supported ZnO film deposited over a silver-coated unclad core of the fiber. A spectral interrogation mode of operation is used to characterize the sensor. In an Ag/ZnO/PVP multilayer system, the absorption of chlorine in the vicinity of the sensing region is performed by the PVP layer and the zinc oxide layer enhances the shift in resonance wavelength. It is, experimentally, demonstrated that the SPR wavelength shifts nonlinearly towards the red side of the visible region with an increase in the chlorine concentration in an aqueous medium while the sensitivity of the sensor decreases linearly with an increase in the chlorine concentration. As the proposed sensor utilizes an optical fiber, it possesses the additional advantages of fiber such as less signal degradation, less susceptibility to electromagnetic interference, possibility of remote sensing, probe miniaturization, probe re-usability, online monitoring, small size, light weight and low cost.

  12. Phase control of Mn-based spinel films via pulsed laser deposition

    International Nuclear Information System (INIS)

    Feng, Zhenxing; Chen, Xiao; Fister, Timothy T.; Bedzyk, Michael J.; Fenter, Paul

    2016-01-01

    Phase transformations in battery cathode materials during electrochemical-insertion reactions lead to capacity fading and low cycle life. One solution is to keep the same phase of cathode materials during cation insertion-extraction processes. Here, we demonstrate a novel strategy to control the phase and composition of Mn-based spinel oxides for magnesium-ion battery applications through the growth of thin films on lattice-matched substrates using pulsed laser deposition. Materials at two extreme conditions are considered: fully discharged cathode MgMn_2O_4 and fully charged cathode Mn_2O_4. The tetragonal MgMn_2O_4 (MMO) phase is obtained on MgAl_2O_4 substrates, while the cubic MMO phase is obtained on MgO substrates. Similarly, growth of the empty Mn_2O_4 spinel in the cubic phase is obtained on an MgO substrate. These results demonstrate the ability to control separately the phase of spinel thin films (e.g., tetragonal vs. cubic MMO) at nominally fixed composition, and to maintain a fixed (cubic) phase while varying its composition (MgxMn_2O_4, for x = 0, 1). As a result, this capability provides a novel route to gain insights into the operation of battery electrodes for energy storage applications.

  13. An Ultrasensitive Organic Semiconductor NO2 Sensor Based on Crystalline TIPS-Pentacene Films.

    Science.gov (United States)

    Wang, Zi; Huang, Lizhen; Zhu, Xiaofei; Zhou, Xu; Chi, Lifeng

    2017-10-01

    Organic semiconductor gas sensor is one of the promising candidates of room temperature operated gas sensors with high selectivity. However, for a long time the performance of organic semiconductor sensors, especially for the detection of oxidizing gases, is far behind that of the traditional metal oxide gas sensors. Although intensive attempts have been made to address the problem, the performance and the understanding of the sensing mechanism are still far from sufficient. Herein, an ultrasensitive organic semiconductor NO 2 sensor based on 6,13-bis(triisopropylsilylethynyl)-pentacene (TIPS-petacene) is reported. The device achieves a sensitivity over 1000%/ppm and fast response/recovery, together with a low limit of detection (LOD) of 20 ppb, all of which reach the level of metal oxide sensors. After a comprehensive analysis on the morphology and electrical properties of the organic films, it is revealed that the ultrahigh performance is largely related to the film charge transport ability, which was less concerned in the studies previously. And the combination of efficient charge transport and low original charge carrier concentration is demonstrated to be an effective access to obtain high performance organic semiconductor gas sensors. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Improved interface growth and enhanced flux pinning in YBCO films deposited on an advanced IBAD-MgO based template

    Science.gov (United States)

    Khan, M. Z.; Zhao, Y.; Wu, X.; Malmivirta, M.; Huhtinen, H.; Paturi, P.

    2018-02-01

    The growth mechanism is studied from the flux pinning point of view in small-scale YBa2Cu3O6+x (YBCO) thin films deposited on a polycrystalline hastelloy with advanced IBAD-MgO based buffer layer architecture. When compared the situation with YBCO films grown on single crystal substrates, the most critical issues that affect the suitable defect formation and thus the optimal vortex pinning landscape, have been studied as a function of the growth temperature and the film thickness evolution. We can conclude that the best critical current property in a wide applied magnetic field range is observed in films grown at relatively low temperature and having intermediate thickness. These phenomena are linked to the combination of the improved interface growth, to the film thickness related crystalline relaxation and to the formation of linear array of edge dislocations that forms the low-angle grain boundaries through the entire film thickness and thus improve the vortex pinning properties. Hence, the optimized buffer layer structure proved to be particularly suitable for new coated conductor solutions.

  15. Metal ion modulated ultrathin films and nanostructures of tyrosine-based bolaamphiphile at the air/water interface

    International Nuclear Information System (INIS)

    Jiao Tifeng; Cheng Caixia; Xi Fu; Liu Minghua

    2006-01-01

    Supramolecular assemblies at the air/water interface from a newly designed tyrosine-based bolaamphiphile, 1,10-bis(O-L-tyrosine)-decane (C10BT), were investigated. The compound could be spread on water surface and form organized ultrathin film. It was interesting to find that metal ions such as Ag + and Cu 2+ in the subphase can greatly modulate the molecular packing of C10BT and the morphology of the subsequently deposited Langmuir-Blodgett (LB) films. Atomic force microscopic measurements revealed that C10BT LB film from the subphase containing Ag + ion showed well-ordered layered nanofibers, while Cu 2+ ion coordinated C10BT film demonstrated dense cross-linked network. It was suggested that both the strong chelating property to the carboxylate and the different packing mode of hydrocarbon chain resulted in the distinct nanostructures. Fourier transform infrared spectra reveal the difference between the Ag-C10BT complex film and that of Cu 2+ ion, and the mechanism of the packing mode of hydrocarbon chain was discussed. Furthermore, the X-ray diffraction and X-ray photoelectron spectra also verified the orderly layer structure and the relative molar ratios compared with different metal ions. While many efforts have been devoted to manipulation of the nanostructures and functions of sophisticated bolaform amphiphiles, we provided a simple method of modulating the organization and morphology of C10BT films through metal ions

  16. Exogenous ROS-induced cell sheet transfer based on hematoporphyrin-polyketone film via a one-step process.

    Science.gov (United States)

    Koo, Min-Ah; Lee, Mi Hee; Kwon, Byeong-Ju; Seon, Gyeung Mi; Kim, Min Sung; Kim, Dohyun; Nam, Ki Chang; Park, Jong-Chul

    2018-04-01

    To date, most of invasive cell sheet harvesting methods have used culture surface property variations, such as wettability, pH, electricity, and magnetism, to induce cell detachment. These methods that rely on surface property changes are effective when cell detachment prior to application is necessary, but of limited use when used for cell sheet transfer to target regions. The study reports a new reactive oxygen species (ROS)-induced strategy based on hematoporphyrin-incorporated polyketone film (Hp-PK film) to transfer cell sheets directly to target areas without an intermediate harvesting process. After green LED (510 nm) irradiation, production of exogenous ROS from the Hp-PK films induces cell sheet detachment and transfer. The study suggests that ROS-induced cell detachment property of the Hp-PK film is closely related to conformational changes of extracellular matrix (ECM) proteins. Also, this strategy with the Hp-PK film can be applied by regulating production rate of exogenous ROS in various types of cells, including fibroblasts, mesenchymal stem cells and keratinocytes. In conclusion, ROS-induced method using the Hp-PK film can be used for one-step cell sheet transplantation and has potential in biomedical applications. Copyright © 2018 Elsevier Ltd. All rights reserved.

  17. A Scale-up Approach for Film Coating Process Based on Surface Roughness as the Critical Quality Attribute.

    Science.gov (United States)

    Yoshino, Hiroyuki; Hara, Yuko; Dohi, Masafumi; Yamashita, Kazunari; Hakomori, Tadashi; Kimura, Shin-Ichiro; Iwao, Yasunori; Itai, Shigeru

    2018-04-01

    Scale-up approaches for film coating process have been established for each type of film coating equipment from thermodynamic and mechanical analyses for several decades. The objective of the present study was to establish a versatile scale-up approach for film coating process applicable to commercial production that is based on critical quality attribute (CQA) using the Quality by Design (QbD) approach and is independent of the equipment used. Experiments on a pilot scale using the Design of Experiment (DoE) approach were performed to find a suitable CQA from surface roughness, contact angle, color difference, and coating film properties by terahertz spectroscopy. Surface roughness was determined to be a suitable CQA from a quantitative appearance evaluation. When surface roughness was fixed as the CQA, the water content of the film-coated tablets was determined to be the critical material attribute (CMA), a parameter that does not depend on scale or equipment. Finally, to verify the scale